MDL-34020: Further work on IMS package importing when using Blackboard packages
MDL-43401 mod_lesson: Fix serving of the pluginfile mediafile
MDL-41693 group: Use standard layout for group related pages
MDL-40139 block_privatefiles: Prevent usage of unmaintained edit page
MDL-39683 Messages, Themes: Fix "my" and "other person" message alignment in RTL mode (theme/clean)
MDL-39683 message: RTL alignment of messages in theme_base
MDL-39684 theme: RTL align of restrictions label in file manager
MDL-41362 theme_bootstrapbase: Alignment of User Selector controls
MDL-41484 theme_bootstrabase: Alignment of labels on smaller screens
MDL-43693: assignment: Fix JS error on grading page.
MDL-40533 block_html: Remove styles specific to the block
MDL-43306 restore: Fix grade_item sortorder after restoring course

While restoring course/activity, restore will blindly insert grade_item
sortorder. Which cause dulicate sortorder and lead to unpredicatble sorting
results.

Now we will call grade_item::fix_duplicate_sortorder() after restore is finished
to fix duplicate sortorder and order grade items to the closest order possible
MDL-41505 theme_bootstrapbase: section actions now visible again
MDL-42682 theme_bootstrapbase: fixed forum search alignment

Conflicts:
	theme/bootstrapbase/less/moodle/modules.less
	theme/bootstrapbase/style/moodle.css
MDL-42682 theme_bootstrapbase: fixed styling of discussion selector
MDL-43675 navigation: courses branch is now recognised as expandable
MDL-43714 blocks: fixed notice when moving to an empty region
Automatically generated installer lang files
MDL-43480 behat: Removing @_only_local tags from steps where it is not necessary
MDL-43480 behat: Adding @_file_upload and @_alert tags

Keeping the previous @_only_local and @_alerts as
this is a stable branch.