Issue #998256 by justafish, Albert Volkman, Dave Reid, no_commit_credit: Please let modules know about the original URL alias in hook_path_update().

- Patch #863318 by carlos8f, andypost, chx, Dave Reid, plach: wrong sort order of aliases for different languages.

- Patch #797680 by lyricnz, jbrown: drupal_write_record() unnecessarily sets primary keys while updating.

- Patch #692044 by Damien Tournoud, effulgentsia: a site with statistics module enabled is much slower in serving cached pages in D7 than in D6.

#587706 follow-up by plach: trim GET['q'] centrally in request_path() so subsequent places don't have to do it.

#282191 follow-up by plach: Remove ambitious parts of translatable fields UI from core that are no longer relevant, given what made it into Drupal 7.

#652420 by sun: Fixed Various failures everywhere caught by asserting on watchdog errors found in testing logs.

#610234 by Gábor Hojtsy, ksenzee, cwgordon7, David_Rothstein, seutje, marcvangend, sun, JoshuaRogers, markus_petrux, Bojhan, Rob Loach, Everett Zufelt, drifter, markboulton, leisareichelt, et al: Added Overlay module to core, which shows administrative pages in a JS overlay, retaining context on the front-end site.

- Patch #613858 by sun, Dave Reid: fixed drupal_is_front_page() should not call drupal_get_normal_path().

#619666 by effulgentsia, casey, and catch: Changed Introduce new pattern for drupal_static() in performance-critical functions.

#320331 by Dave Reid, dww, John Morahan, cwgordon7, moshe weitzman, c960657, and smoothify: Turn custom_url_rewrite_inbound() and custom_url_rewrite_outbound() into hooks.