MDL-41117 theme_formal_white: fixed border around header of course categories and sub-categories
MDL-37028 Integrity check for course modules and sections

created function, unittest, build-in quick integrity check on each call to rebuild_course_cache()
also added CLI script
MDL-40733 mod_forum: added the forum name to some pages that were missing it
MDL-40631: Prevent students from submitting empty assignments.
MDL-39992 assign: Sort grading actions in alphabetical order
MDL-23335 mod_forum: allow multi-lang filtering of shortened messages
MDL-37028 Integrity check for course modules and sections

If section mentioned in 'orphaned' module does not exist module is added to the first available section. Also corrected whitespaces
MDL-41565 event: Correct inclusion path of observers includefile
MDL-41305 group: Form improvements for group/grouping creation
MDL-40833 Course - Single topic pages need h3 for section heading
MDL-41408 redirect after incorrect login attempts
MDL-41189 fixed overflow issue with filepicker thumbnail
MDL-40686 book: fix heading level and styling
MDL-40736 Survey: improve heading levels and styling
MDL-41564 folder resource: fix page heading levels
MDL-41566 page resource: fix page heading levels.
Also removing printheading options setting.
Merge branch 'wip-MDL-37028-master' of git://github.com/marinaglancy/moodle
Merge branch 'wip-mdl-23335-master' of https://github.com/deraadt/moodle
MDL-23335 forum: Fix whitespace
MDL-21415 reports: Adding support of groups to course participation reports

Also introducing new api groups_allgroups_course_menu() that generates a selector for all groups in course"