MDL-48144 upgrade: add v2.8.0 sep lines
MDL-48168 quiz editing: max grade should be editable after attempts

Note that there was a lot of legacy code left from Moodle 2.7 which is
no longer required, and I took this opportunity to delete it.
MDL-48156 task: Skip the scheduled task only for really disabled plugins
MDL-39376 enrol: Optimized setting for ldap and database
Merge branch 'MDL-48168_28' of git://github.com/timhunt/moodle into MOODLE_28_STABLE
MDL-48093 HTML 5 video: Firefox now supports .mp4
MDL-47975 assign: Stop gap fix for random time fails.
MDL-47502 test_statslib_cron_daily: fix provider

Fiddling with the database in the data provider causes "out of sync"
errors when running suite tests.
MDL-47502 statslib tests: improve test

While integrating I noticed some problems which already existed in this
test:
* The enrolment data generator was not used
* The student roleid was hardocded
* The role assignment was at site level..
MDL-30968 mod/forum Fixed group link
MDL-39692 grade: Ability to delete letter boundary
MDL-39692 grade: Little code clean up of letter boundary deletion
MDL-47391 Update pagelayout for default profile configuration
MDL-30968 mod_forum: No picture link to group when no groups mode
MDL-48174 core_lang: support for ->skiplangupgrade in lang cron task

Similar to upgrade_language_pack(), update_langpacks_task should
respect skiplangupgrade config. Also, this should be added to behat
whitelist, so it can be disabled during on-sync period, when lang
pack for master is not available.
MDL-48174 tool_langimport: info about skipped update

So admins can work out why the task might not be having an effect.
weekly release 2.8+