Update test framework:

* Allow specific groups to be tested
* Update tests to include MediaFeatures group
Update readme file
CE-86 add permission welcomeexempt to STAFF group
CE-990 add $variable_id to Log (it was missing)
CE-990 correct code format
CONN-622 wall notification admin entity was always empty; changing the array key name fixed isse with not displaying removals of messages in thread history
MAIN-3073 add processData and contentType parameter to ajax request in nirvana.js
CONN-622 | Fix for removing Wall replies
CON-2022 | maintenance script for fixing broken removed wall replies
CONN-622 | Wall removing replies - one more fix
Merge pull request #5167 from Wikia/MAIN-3073

MAIN-3073 add processData and contentType parameter to ajax request in nirvana.js
ADEN-1512 Fix alignment of MOBILE_TOP_LEADEBOARD
Merge pull request #5210 from Wikia/aden-1512-fix-mobile-leaderboard-alignment

ADEN-1512 Fix alignment of MOBILE_TOP_LEADEBOARD
MWEB-1028: prevent reloading the page after submiting the form by hitting enter
Merge pull request #5187 from Wikia/CONN-622

CON-2022 | Fix for removing Wall replies + maintenance script
MWEB-1028 prevent submiting the form on hitting enter while creating POI categories
MWEB-1028: modal.$element is already a jQuery object no need to wrap it with $()
ArticleComments / Wall: wrap Bucky calls in if statement

This is The Quick&Ugly Fix (TM) for P2

Backporting #5208
CON-1820: fix empty space when hubs menu doesn't have 7 hubs to display
GlobalNavigationController: run stylize.php