MDL-41173  Change enrolenddate from "date_selector" to "date_time_selector"
MDL-43266 Testing sites are cleaning all test dataroot contents
MDL-44095 frontend: fix typos in readme file
MDL-44451 fix plugin_misplaced_exception exception
MDL-44061 Ajax: Log whitespace issues to the server error log
MDL-44345 repository_youtube: Endless loop when reaching last results
MDL-43721 Assign: Static cache for plugin is_enabled and is_visible because they get used alot
MDL-44478 Javascript: Remove duplications in simpleyui rollup
MDL-43721 Assign + groups: Improve performance of assign grading table

Add a function to the groups lib to filter a list of users down
to the ones who can see the module. Required because calling
groups_course_module_visible() for a list of users is too slow
and we shouldn't spread group logic outside of grouplib.php.

Using it in the assign grading table reduces DB queries from 6198/1 to 256/3.

This is 12secs down to 2.5secs.
MDL-44480 Javascript: Correct dialogue ID generation
MDL-44359 fix explode(', ', regressions from MDL-44255
MDL-32699 wiki: only edit capability is required to restore wiki revision
MDL-40721 wiki: missing page->set_url() when restoring wiki
MDL-43966 events: link to migration wiki in lib/upgrade.txt
MDL-44337 glossary: behat test for glossary categories
MDL-44471 Revert "MDL-42238 mod_wiki: Alternate name sql update to wiki_print_recent_activity"

This reverts commit 6d3d9bd927d5386b1dc4fbbcb7db5559efa7a5cd.
MDL-42870 completion: show failed activities as incompleted
MDL-42870 completion: performance and readability code refactoring
MDL-44496 fix event buffering in log stores
MDL-44496 fix minor trait docs issue

The store trait is not necessary any more in bufferef_writer
because we define the required methods as abstract.