This just deletes all the upgrade steps previous to 2.7.0. Some
small adjustments, like adding missing MOODLE_INTERNAL or tweaking
globals can also be applied when needed.
Next commit will get rid of/deprecate all the upgradelib functions
not used anymore in codebase.
Updated the help text on the theme settings page to
mention that the theme logo will only be displayed on
the front page and login page.
Conflicts:
theme/upgrade.txt
version = planned 2015051100 release version
requires= current 2015050500 rc1 version
Note: On purpose, the course format social wrong version (2015102100)
has been kept unmodified. Looking forward a solution right now.