This reverts commit 24c357b5.

Issue #1359326 by xjm: Fixed t() documentation does not clearly indicate that  options are documented in format_string() docs.

Issue #1006714 by Steven Jones, chx, mr.baileys, xjm, carlos8f: Fixed drupal_get_path() doesn't work for profiles.

Issue #673020 follow-up by attiks: Critical fix to Content-Language HTTP header to not cause issues with Drush.

Issue #1295502 by pillarsdotnet: Fixed Add missing '$' character to docblock for timer_start(), timer_read(), and timer_stop() functions.

Issue #76824 by geerlingguy, xjm, droplet, kbahey: Change notice for Drupal should not handle 404 for certain files.

Issue #402896 by berdir, catch, andypost, dmitrig01, chx, pounard, sun, sdboyer: introduce DrupalCacheArray and use it for drupal_get_schema().

- Patch #804864 by fabsor, pwolanin, catch, c960657: external page caching does only work when 'page_cache_invoke_hooks()' is set to FALSE. (Old 'Aggressive Mode' is on).