- Patch #19451 by JonBob: improved consistency of module descriptions.  We should write guidelines for this -- maybe in the PHPDoc code of the _help hook.

- Patch #18093 by Junyor: clean up handling of image toolkit code in absence of
  any toolkits.

- Patch #13738 by TDobes: theme system fixes:

* Fix a bug which would cause the "configure" link for styles to be broken.
* Fix a bug with using drupal_get_filename for theme engines. Although this is not called anywhere in core, we should still fix it for contrib. (i.e. themes that may want to manually invoke a theme engine to create a hybrid theme)
* Correct an inaccurate comment in theme.inc
* Populate the default primary links with an "edit primary links" link for consistency with the secondary links
* remove some unnecessary variables in the theme administration which had misleading and confusing names
* replace time-consuming foreach when rendering theme admin page with a more efficient array_key_exists
* usability: rather than completely removing the search box checkbox when search.module is disabled, simply disable it. (UI elements shouldn't appear/disappear.)

  breaks your Drupal.  Only themes in './themes/subdir' are picked up now.

    - permissions menu link updates in a number of modules help
    - anchor link fix in distributed auth help
    - "my account" link fix in user help
    - spelling correction in tracker.module help

- I also changed 'admin/access/perms' to 'admin/access/permissions'.

- Patch #16358 by James: added toolkit to enable better image handling.  The avatar code and the upload module have been updated to take advantage of the new image API.

There are 5 main functions that modules may now utilize to handle images:

* image_get_info() - this function checks a file.  If it exists and is a valid image file, it will return an array containing things like the pixel dimensions of the image, plus the 'type' and common extension.
* image_scale - resizes a given image to fit within a given width / height dimensions, while maintaining aspect ratio (not distorting the image).  This function can be used to generate thumbnails, or ensure a maximum resolution, etc.
* image_resize - similar to image_scale (but will not respect aspect ratio - may well distort the image).
* image_rotate - rotate an image by X degrees
* image_crop - crops an image to a given rectangle (defined as top-left x/y coordinates plus a width & height of the rectangle).

Contribution modules will now be able to rely on these base manipulation functions to offer additional functionality (such as image nodes, photo galleries, advanced image manipulation, etc).

  Modified the patch to remove some redundant code, to translate strings, and to better use the menu system.

- Patch #15570 by Drumm: integrated the admin and system module.  Renamed the callback as per Goba's suggestion.

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

- Patch #5942 by TDobes: fixed theme stuff after multi-site configuration patch.

    + added support for multi-site configurations.
    + tidied up some old cruft and added code comments.

- 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

- Fixed bug #9948: added some checks to system_setting_save() to avoid PHP warnings/errors.

- Simplified/reorganized version of patch #9620 by Jeremy: fixed errors when writing to cache.

- Patch #11001 by Philippe: added support for dates in ISO-8601 format.

- Patch #10730 by Adrian: made it possible to upload a logo.

#10441: Splitting up upload permissions in 2: one for uploading and one for viewing/downloading. It does not make sense to only allow downloading for people who can upload themselves.

- Patch #8179 by JonBob: reintroduced menu caching.

- Patch #10668 by drumm: moved the 'first day of week' settings to the system module for other modules to reuse.  This is considered to be a usability improvement because it simplifies some pages/workflow.

Upload.module
- Fixing a bug caused by the PHP5 patches.
Beware: PHP4's array_merge() will silently accept objects and convert them to arrays. We should not depend on this behaviour in the future.

File.inc / file-using modules:
- Removing the constant FILE_SEPARATOR: forward slashes work fine on Windows, and it was being used incorrectly as an URL separator sometimes.
- Adding @ to mkdir and chmod to supress ugly PHP errors. They are already reported with drupal_set_message().
- Fixing default for variable 'file_directory_temp'.
- Clarifying the help tip for 'file_directory_temp' in admin > settings.