MDL-45486 Bump all versions to planned release

This bumps all versions to planned 2.7 release
(2014051200) version and all the dependencies to
current 2.7rc2 (2014050800)
Automatically generated installer lang files
MDL-45296 mod_assign: Revert changes to lock_submission and unlock_submission events
Merge branch 'MDL-45486' of git://github.com/stronk7/moodle
MDL-45486 Bump all versions to planned release
Merge branch 'install_master' of https://git.in.moodle.com/amosbot/moodle-install
on-demand release 2.7rc2+