#523058 by catch, sun, c960657, smk-ka, pwolanin, andypost: optimize calls to check_plain() by trying to use new PHP 5 features and inlining UTF-8 checking

#320171 by Deve Reid, jbrauer: fix return value passing by reference in bootstrap.inc's IP address checking

#732064 follow up by pwolanin: move lock system loading earlier to avoid stepping over it or attempting to use it before it is loaded

#251792 by pwolanin, Damien Tournoud, slantview, c960657: added a locking framework for long running operations; solves rebuilding issues with menus and the locale cache

#203323 by JirkaRybka, robertgarrigos, lilou, thePanz, c960657, sun: move the LANGUAGE_* constants to bootstrap.inc and remove several defined() checks on them now that they are always defined

#346285 by grendzy, Damien Tournoud, thekevinday et al: fixed problem when HTTP_HOST is not transmitted

#323474 by gpk, Dave Reid, catch: hook_boot() was not called on non-cached pages when agreesive caching was on

#324875 by pwolanin: improve HTTP_HOST checking, ensuring that the host is lowercased and only valid characters are allowed.

#225880 by pwolanin, keith.smith: get the user create settings.php instead of Drupal, so upgrading getseasier

#50901 by chx: do not allow user login under maintenance mode, if the logged in user has no site config permission

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

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

#173408 by markus_petrux / add1sun: move proxy IP configuration options to settings.php, because these need to be used before Drupal has the variables loaded from the database

#190283 by myself and JirkaRbyka: use get_t() in pre-database setup code, add missing javascript key to language objects (kills notices) and document st() better

#182675 by chx: fix caching bootstrap, so hook_boot() and the timer is called when required, integrating the cache init function right into the bootstrap

#163785 by Eaton, dvessel and quicksketch: theme .info files should be able to override core and module CSS files based on file basenames

#172262 by JirkaRybka: better globals handling in install system, so the choosen profile and language are remembered

#173227 by Desbeers: make language listing work early in the bootstrap, when modules are not yet loaded (fix a regression from a previous patch)

 - make searches work again, better worded
 - do not cache English stuff
 - fix strike through on string seek page
 - fix exports for translations

#151868 by chx: avoid using array_shift() because it takes a lot of time to rehash the array, so indexing the array is more performant, then shifting items one by one