command to delete all student related data
refactor forum html and css
refactor the if theme forum css
fix navbar layout
refactor forum html and css from timtec theme
show thumbnail on course intro
Merge branch 'hotfix-thumbnail-course'

Conflicts:
	themes/default/templates/course.html
include alert messages on actions menu, fix layout
fix default theme alerts layout
fix and improve messages
remove unused flags and comented code
refactor alerts layouts to centralize it on default and if theme
feedback message on notes panel
delete save button from activities, move delete button to header
move lessons nav up to the title header
fix header's layout issues, refactor css, put unit title on lesson page,
fix layout of delete unit button
fix user list layout on messages modal
Merge branch 'messages-issue-3459'
forum errors' message layout