- Modified patch #19694 by chx: makes sure that block.module deals by default only with regions 0 and 1 as it does now but lets you use block_list with any region you define. This opens many possibilites. You may do a multi region module, with your admin UI using the blocks table as storage and the block_list matcher. Or you may do a sections module using the block matcher without cluttering the current blocks list.

- Patch #18382 by Neil: usability improvement: organized the blocks on the block administration page by region. (I wanted to do that myself!)

- Patch #16074 by Andre Molnar: add configuration option to show blocks only on pages of certain node type.

- Removed some cruft: left-over xxx_help_page() functions.

- Patch #14209 by nysus: improved the clarity and readability for a group of radio buttons for a block's visibility settings.

- Patch #12353 by Stefan: usability improvement: don't show 'throttle fields' unless the throttle module is enabled.

- Patch #12783 by Stefan: various small consistency/usability improvements.

   + throttle module: flush cache when the throttle enables/disables
   + throttle module: prevent throttle being enabled by 0 users or guests when disabled
   + system module: remove requirement for statistics.module
   + block module: update help text to reflect access log is no longer required
   + statistics module: throttle is now enabled/disabled, not using levels 0-5

  * There are only two throttle levels instead of 5, namely 'enabled' and 'disabled'.  This makes it a _lot_ easier to predict when the throttle will kick in.  However, if you maintain a module that is throttle-aware, it needs to be updated!

  * The throttle mechanism now uses the current number of anonymous users or the current number of authenticated users to kick in.  This is a _lot_ more intuitive than the old throttle mechanism.

  * The throttle block has been removed -- you can now use the "Who's online" block to determine the good throttle settings.

  * Most of the documentation has been removed because it was deprecated.

  * It's less code!

The primary goal of this patch is to take the 'custom' and 'path' columns of the block overview page and make them into something understandable. As of Drupal 4.5 'custom' lacked an explanation which wasn't buried in help text and path required dealing with regular expressions.

Every block now has a configuration page to control these options. This gives more space to make form controls which do not require a lengthy explanation. This page also gives modules a chance to put their block configuration options in a place that makes sense using new operations in the block hook.

The only required changes to modules implementing hook_block() is to be careful about what is returned. Do not return anything if $op is not 'list' or 'view'. Once this change is made, modules will still be compatible with Drupal 4.5. Required changes to core modules are included in this path.

An additional optional change to modules is to implement the additional $op options added. 'configure' should return a string containing the configuration form for the block with the appropriate $delta. 'configure save' will come with an additional $edit argument, which will contain the submitted form data for saving. These changes to core modules are also included in this patch.

- Patch #10677 by drumm: removed dead code.  Leftover.

   + Made error strings in blog.module consistent.
   + Explained a bit better what the RSD setting is for in the blog module.
   + Removed the notes about PHP content from block module and book module, since everything is handled via the input formats now.

- Adding a drupal_goto to the block admin.

- Patch #8179 by JonBob: reintroduced menu caching.

- Patch #10622 by Adrian: fixes various PostgreSQL related problems.

  1) Menu problems with Postgres (this is a highly critical 1 line fix)
  2) Archive module fails with Postgres
  3) Postgres setup problems - changes to database.pgsql (although i made these changes myself before finding this patch)
  4) Book module fails with Postgres
  5) Postgres problems following creation of a new type of user - which is actually about a taxonomy.module bug.
  6) Creating accregator_item_table in PostgreSQL
  7) Postgres - Polls not displayed on Poll Page
  8) Blog module has sql errors with postgres

  This should not affect MySQL users (hopefully).

- Patch by JonBob: for consistency and readability, add brief descriptions of each source file inside the @file comment block at the head of the file. This helps with Doxygen indexing, and also allows neophytes to see what a file does immediately on opening the source, regardless of the organization of the hooks.

- Code improvements by Stefan: use capital letters for header titles (and added some missing t() functions).

- Patch #9983 by Stefan: usability improvement: made sure all status messages start with a capital letter.

The Input formats - filter patch has landed. I still need to make update instructions for modules and update the hook docs.

Here's an overview of the changes:
1) Multiple Input formats: they are complete filter configurations (what filters to use, in what order and with which settings). Input formats are admin-definable, and usage of them is role-dependant. For example, you can set it up so that regular users can only use limited HTML, while admins can free HTML without any tag limitations.
The input format can be chosen per content item (nodes, comments, blocks, ...) when you add/edit them. If only a single format is available, there is no choice, and nothing changes with before.

The default install (and the upgrade) contains a basic set of formats which should satisfy the average user's needs.

2) Filters have toggles
Because now you might want to enable a filter only on some input formats, an explicit toggle is provided by the filter system. Modules do not need to worry about it and filters that still have their own on/off switch should get rid of it.

3) Multiple filters per module
This was necessary to accomodate the next change, and it's also a logical extension of the filter system.

4) Embedded PHP is now a filter
Thanks to the multiple input formats, I was able to move the 'embedded PHP' feature from block.module, page.module and book.module into a simple filter which executes PHP code. This filter is part of filter.module, and by default there is an input format 'PHP', restricted to the administrator only, which contains this filter.
This change means that block.module now passes custom block contents through the filter system.
As well as from reducing code duplication and avoiding two type selectors for page/book nodes, you can now combine PHP code with other filters.

5) User-supplied PHP code now requires <?php ?> tags.
This is required for teasers to work with PHP code. Because PHP evaluation is now just another step in the filter process, we can't do this. Also, because teasers are generated before filtering, this would result in errors when the teaser generation would cut off a piece of PHP code.

Also, regular PHP syntax explicitly includes the <?php ?> tags for PHP files, so it makes sense to use the same convention for embedded PHP in Drupal.

6) Filter caching was added.
Benchmarking shows that even for a simple setup (basic html filtering + legacy URL rewriting), filtercache can offer speedups. Unlike the old filtercache, this uses the normal cache table.

7) Filtertips were moved from help into a hook_filter_tips(). This was required to accomodate the fact that there are multiple filters per module, and that filter settings are format dependant. Shoehorning filter tips into _help was ugly and silly. The display of the filter tips is done through the input format selector, so filter_tips_short() no longer exists.

8) A more intelligent linebreak convertor was added, which doesn't stop working if you use block-level tags and which adds <p> tags.

- Patch #9330: ucfirst() gives problem when used with multibyte charset.
  Replaced the use of ucfirst() with a CSS-based solution.