#201536 by chx: centralizing permission checking code in node revision handling, removing lots of duplicate code

 - possible timeouts with installing/enabling lots of modules at once in core
 - enable install profiles to have more modules without fear of timeouts on install
 - bootstrap Drupal before each module load, so previously enabled modules are bootstrapped
 - let modules run their hook_requirements() (although actually calling them will be possibly fixed in another patch)

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

#196410 report by daniel.soneira, patch by myself, tested by Freso: several fixes to url() generation and path aliasing, fixing path aliases for node paths and front page links in themes

#141727 follow up by dvessel: handle developer edge case in theme handling when database is active, but tables are not there

#141727 by merlinofchaos, dvessel, sun: restore themeability support for maintenance pages (regression)

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

- Patch #192242 by catch, quicksketch, webchick, keith et all: usability improvements for the vocabulary/term forms.

#184876 by dijnz, merlinofchaos and myself: non-phptemplate files were not discovered - implement proper extension chopping

#181564 by Crell: add first and last CSS classes to menu tree lists and themed item lists for themers to use

#177473 by chx, quicksketch, dvessel and merlinofchaos: make it possible for modules to add their own theme variable preprocess hooks and improve documentation on the different preprocess options

#180389 by merlinofchaos: add hook_theme_registry_alter() for devel module and friends to alter and get access to the theme registry

#178973 by merlinofchaos: proper style and script inheritance between themes more then two levels deep in the hierarchy

#176084 by Stefan Nantegaal and dvessel: fix notices in theme.inc, when specific sidebars are not set

- Patch #160395 by dvessel and merlinofchaos: allow theme engine to register theme variable functions.

#165343 by merlinofchaos and dvessel: include path history in theme discovery suggestions, so we find subtheme files properly

#166071 by jjeff and dvessel: move default template preprocess code to template_preprocess, and add *lots* of documentation to template files and functions

- Patch #168028 by dvessler, merlinofchaos, pwolanin et al: both theme functions and templates may need include files. Flush your caches.

- Patch #145218 by profix898, bennybobw, Crell, forngren et al: use href instead of @import for CSS.

#166593 by hswong3i: move literal values out of some core queries to support cross-database compatibility (ie. better SQL parsing and altering options)

#160168 by kkaefer and pwolanin: restore lost Drupal 5 functionality of being able to set primary and secondary links differently

#168587 by jjeff: add rel=nofollow attribute to anonymous comment home page links to counter some spamming