Issue #1049284 by xjm: Fixed Running update.php to flush caches no longer works unless there are updates pending.

Issue #951644 by catch, David_Rothstein, aschiwi, xjm: Fixed Requirement warnings (e.g. for PHP memory limit) are not shown on install or update unless there is a requirement error also.

Roll-back of Issue #534594 by beejeebus, catch: This causes fatal errors from class loaders in certain modules (CTools, etc.)

#1013808 by threewestwinds, redndahead: Fixed update.php displays misleading messages for modules that return no messages.

#864464 follow-up by David_Rothstein: Move notice about requiring latest version of Drupal so it only comes up the first time update.php is ran.

#864464 by heyrocker, Beanjammin: Ensure people using Drupal < 6.16 that they must upgrade to latest version, rather than showing them a WSOD.

- Patch #789464 by pwolanin: update.php has a fatal error if any module extends a core stream wrapper class.

- Patch #348448 by mfb, c960657, marvil07, cdale, jpmckinney: fixed PHP strict warnings when running tests and for PHP 5.3.

- Patch #732486 by Damien Tournoud, JacobSingh: drupal_add_http_header()  req ; make Status a normal header and drupal_add_http() header shouldn't return a list of headers.

#211182 by Damien Tournoud, David_Rothstein, clemens.tolboom, scor, hunmonk, et al: Allow updates to specify dependencies to ensure they run in a predictable order.

#653956 by moshe weitzman and catch: Create {cache_bootstrap()} in update_prepare_d7_bootstrap() to fix yet another problem in the update path.

#547068 by sun, seutje, yoroy, Gábor Hojtsy, adrian, Bojhan, and markboulton: Use Seven theme for installation / updates.

#571086 follow-up by sun: Allow specifying a 'wrapper callback' before executing a form builder function.

#67234 by Ralf, Dave Reid, David_Rothstein, Rob Loach, dww, et al: Added a permission to update.php.

- Patch #572618 by effulgentsia, pwolanin, sun: all theme functions should take a single argument. Code clean-up and performance improvement. Woot.

- Patch #557542 by CorniI, catch, fago, Crell, sun | pwolanin, chx, webchick, mattyoung, alexanderpas, justinrandell, dropcube, moshe weitzman, Damien Tournoud, Rob Loach, Dries: cache module_implements() for better performance and scalability.

- Patch #570572 by winston, David_Rothstein | Shai, Xano, alexanderpas, emmajane, kazar: changed label for user/1 account from 'administrator' to 'site maintenance account'.

- Patch #460320 by catch, fago, Frando: standardized, pluggable entity loading for nodes, users, taxonomies, files and comments.

#497118 by chx, catch, pwolanin, JoshuaRogers, and Jacob Singh: Remove the function registry. While the hope was that this would result in improved performance for low-end hosts, it comes at the expense of critical development experience problems and less benefit than something like APC. Class registry remains intact to facilitate autoloading.

Of all the patches to accidentally commit without a message. :( Rolling back registry rip. Let's try that again.