#281405 follow-up by Arancaytar, catch, Crell, and justinrandell: Reduce memory consumption of menu_rebuild() by splitting huge query into multiple passes.

#370537 by chx, sun, effulgentsia, quicksketch, eaton, Heine, and yched: Allow buttons to only validate sections of forms, e.g. More buttons. (with tests)

#399642 by sndev and carlos8f: Make drupal_install_modules() resolve dependencies and trigger an error when they do not exist. (with tests)

- Patch #634310 by casey: small improvement of drupal_render(): conditionally call element_children().

- Patch #357021 by Kars-T, yched: fixed #after_build_done() set after first after_build() function was run, instead of all after_build() functions.

- Patch #671884 by axyjo, int: setting the date to 2010 in the COPYRIGHT.txt file. Welcome to the new year, Drupal.

- Patch #437018 by JamesAn: convert form_options_flatten() in form.inc to use new static caching API.