MDL-44486 core: Rewrite JavaScript progressbar
MDL-44620 behat: Automates MDLQA-6

- MDLQA-6: By default, a new course contains a news
forum in which only teachers can post and subscription
is forced
MDL-44620 behat: Automate MDLQA-7

- MDLQA-7: By default, a new course contains a Latest
News block which displays a specific number of recent
discussions from the news forum
MDL-41313 mod_forum: Remove deprecated post_form.php
MDL-45627 mod_fourm: Move subscriber classes to separate class files
MDL-45658 events: included enrolment method in the user_enrolment_deleted/updated event descriptions
MDL-45677 mod_assign: removed treatment of an array as an object
MDL-18162 mod_forum: Correct phpdoc for forum_clean_search_terms
MDL-40371 Upgrade-until-22: remove obsolete _upgrade_grades functions
MDL-44054 quiz_statistics fix lang string concatenation.
MDL-45592 mod_feedback - unwanted linebreak after import or duplicating a feedback
MDL-45513 cache: added support to unit tests for alt cache stores
MDL-45513 cache: implemented defines for unit testing alternative caches
MDL-45333 output: navbar is now wrapped in a <nav> tag
MDL-41665 scorm : Rewriting using html_writer
MDL-45781 quiz autosave: detect and report when the session is lost.

and also other errors.
MDL-45630 events: removed unnecessary 'the' from event descriptions
Merge branch 'MDL-18162-master' of git://github.com/andrewnicols/moodle
Merge branch 'MDL-45781' of git://github.com/timhunt/moodle
MDL-44098: Late submissions with extension calculate period of lateness incorrectly