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)
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