Issue #825972 by daniels220, Reidsy, Albert Volkman: add phpdoc documentation to sess_read() and sess_write()
Issue #1174496 by Eric_A, grendzy, greg.1.anderson, c31ck: drupal_error_handler() should not assume filter_xss() is available. It might be called before that is loaded. Also fixes Drush compatibility.
Issue #883038 by pillarsdotnet, ShutterFreak, anarcat: ereg() and ereg_replace() are deprecated but Drupal 6 will not migrate to preg to avoid breaking APIs, so we need to silence the warnings coming out of the use of ereg on PHP 5.3+
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 #504506 by andypost, pillarsdotnet, podarok: Drupal.formatPlural() did not pass on extra arguments for translations of some plural values
Issue #556842 by mh86, catch, bangpound, wojtha, deviantintegral: optimize taxonomy_get_tree() by building the tree internally instead of recursively to improve performance; especially good for bigger taxonomies
Issue #156582 by c960657, drico, pwolanin, townxelliot, Damien Tournoud, kbahey, mikeytown2, jpmckinney, craig_, zyxware: add missing timeout support to drupal_http_request() to avoid Drupal hanging on web service requests
Merge remote-tracking branch 'vanilla/6.x' into pressflow-plus-dev

Conflicts:
	includes/bootstrap.inc
Issue #147000 by Berdir, Dave Reid, pwolanin, pillarsdotnet, TR, jbrauer, dstol: rework module_rebuild_cache() and system_theme_data() to support locking, so that concurrent requests will not corrupt the data; fixes an issue where themes got disabled occasionally
Issue #269877 by neochief, roderik, akaliel, mathieu, jct, Jo Wouters, fago, ufku, fmjrey, nonsie, pfournier: avoid duplicate paths (again) in path_set_alias()
Issue #720876 by pillarsdotnet: user_register_validate() should invoke user_module_invoke() with an account object rather than an array; improved PHP 5.3 compatibility
Issue #767104 by mgriego, EugenMayer, mkalkbrenner: taxonomy_node_save() should refresh the node terms (especially for free tagging vocabularies) when nodes are updated, so they are kept up to date in the same HTTP request
Issue #648516 by cafuego, williamestrada: node_build_filter_query() should consider the vid of nodes when joining on term_data to consider only current revisions of nodes
Issue #1137848 by pillarsdotnet, BrockBoland, tim.plunkett: hide /filter/tips page from well behaving search engines, it is pointless to be included in search indexes
Issue #336483 by brianV, catch: add index for comment_count on column in node_comment_statistics to avoid full table scan when search index is updated for example
Issue #975754 by jhodgdon, Albert Volkman: fix phpdoc about access callback inheritance for menu items
Issue #1278160 by tim.plunkett: lower the severity level in watchdog() for orphaned actions
Issue #289504 by mikeryan, catch, moshe weitzman: backport indexes from Drupal 7 on comments and node_comment_statistics to improve performance of mass-user operations such as deleting users en masse
Issue #600836 by tim.cosgrove, dww, naxoc, Dave Reid: prevent batches from going indefinitely if their 'finished' value becomes bigger than 1
Issue #12274 by markoshust, DamienMcKenna, seanbfuller, cburschka, aufumy: do not accept email addresses with dots at the end as valid