Issue #1173012 by carlos8f, Fabianx, Gábor Hojtsy: do not remove blocks for disabled modules in _block_rehash() to avoid blocks disappearing for people following the update guide to the letter disabling contrib modules when updating Drupal core

Issue #235673 by yched, Damien Tournoud, swentel, pwolanin, redndahead, sun, carlos8f, c960657: Changes to block caching mode not caught

Issue #335621 by Dave Reid, jrguitar21, jhodgdon: fix PHP strict warning by initializing object in template_preprocess_block_admin_display_form()

#554992 by Davy Van Den Bremt, jhodgdon: code documentation for block_box_get() and block_box_save()

#315739 by sun: The theme name is in arg(4) on the block admin page, so only redirect to theme specific page if that is set.

- Patch #302518 by AlexisWilke: fixed problem with PostgreSQL users not being able to delete blocks.

#252921 by David_Rothstein and agentrickard: remove unused join, which caused column type compatibility problems with postgresql; improves postgresql compatibility

#232037 by pwolanin: (performance) block regions should only be populated when called for, not in all cases (fixes performance expectation on 403/404 pages)

#157652 by beginner, Steven Merrill and killes: block_user() had a global user object and a user parameter colliding

#211742 by theborg, chx: detect and solve the problem when blocks are assigned to invalid regions (happens in theme development)

#202425 by keith.smith: standardize reference to block placement page as 'blocks administration page' to avoid any confusion

#192779 follow up by Lynn: only show enabled themes on block admin page *and* the admin theme (which might not be enabled)

#199890 by gaele, keith.smith: improve block module help text, include description of drag and drop and better help about the throttle functionality; also comes in smaller chunks which makes it easier to translate and update later

#199832 by theborg, Pasqualle: block title defined as NOT NULL, so requires a default empty string even if not set (fixes a theme notice but also a pgsql error)

- Patch #164532 by catch, pwolanin, David Strauss, et al.: improve table indicies for common queries.

#192779 by gaele: (usability) only show theme tabs on the blocks page for enabled themes, for consistency with the theme settings page

#200069 by keith.smith: new standard for 'more information' links in module help texts, as the handbook we referred to before was renamed

 - whitespaces at end of lines
 - indentation
 - control structure usage
 - whitespace in empty lines
 - phpdoc comment formatting

- Patch #163246 by keith smith, freso, O Govinda, catch, webchick et al: fixed minor spelling issues and fixed spacing issues.

#80963 by chx with multiple contributors: remove deletion and database lock based block rehash code, replace it with simpler updates

#184867 by deekayen, catch and keith.smith: fix some spelling errors in our source code and messages printed

#183690 by Wim Leers: (developer improvement) abstract path matching to drupal_match_path() from block listing, so this gets reusable when path based matching is required