Fix various colorization issues in Monobook

This commit addresses several color problems in the Forum and WikiaStyleGuide extensions caused by pulling colors set in the Theme Designer for the Oasis skin.
Fix out-of-place black background
Additional colorization fixes (VOLDEV-36)
code cleanup
VOLDEV-47 - Add select all button to Special:ListUsers
Merge branch 'dev' into VOLDEV-36

Conflicts:
	extensions/wikia/Forum/css/RelatedForumDiscussion.scss
enforced VOLDEV-36 changes
use .prop() over .removeAttr()
set check using .prop() too
VOLDEV-36: Separate Monobook styling
VOLDEV-36: include mixins
Merge branch 'dev' into VOLDEV-36

Conflicts:
	extensions/wikia/Wall/WallHistoryController.class.php
Add newlines
CON-1016 | Old global Header ABTest removal
CON-1016 | Old GlobalNavigation removal
CON-1016 | Global header User menu
Barebone version of hubmenu
CON-1016 | Global header login dropdown
hubmenu progress
CON-1016 | GlobalHeader avatar + rest of changes
CON-1016 | Global header font color change