MDL-37410 External PHPunit test: used ->getDataGenerator()->enrol_user instead to manually enrol the user. + improve the unassignUserCapability to remove a capability assigned by getDataGenerator->enrol_users
MDL-35883 Accessibility: Added title for user link in header and footer for accessibility
MDL-35883 Accessibility: Added title for login as user link in header and footer for accessibility
MDL-38254 Assignment Module: add avaialble message to all assignment types
MDL-38030 new core_user_get_users_by_field function deprecates core_user_get_users_by_id
MDL-38933 Assign - improved wording for help string.
MDL-22153 backup: delete old, unused, 1.9 files
MDL-38999 timezones: fix maxyear handling on rule calculation.
MDL-38999 timezones: fixed timezone information.
MDL-38935 quiz autosave: save HTML editor contents.

Also, ignore changes in scrollpos.
MDL-38999 timezones: add some TZ/stamps know to be problematic to tests.
MDL-39059 Set explicit boolean type of a hidden field in workshop random allocator form
Merge branch 'MDL-38999' of git://github.com/stronk7/moodle
Merge branch 'MDL-37410-master' of git://github.com/mouneyrac/moodle
Merge branch 'MDL-39059-workshop-settype' of git://github.com/mudrd8mz/moodle
Merge branch 'MDL-22153' of git://github.com/stronk7/moodle
Merge branch 'MDL-38933-master' of git://github.com/damyon/moodle
Merge branch 'MDL-38030-master' of git://github.com/mouneyrac/moodle
Merge branch 'MDL-38935' of git://github.com/timhunt/moodle
MDL-39041 Assignment - Fix regression in "allow submission changes".

A typo was introduced in the assignment attempt history feature that broke
unlock submissions. This was detected by the new behat test in MDL-38970 (yay).