WikiaSkin: introduce WikiaSkinTopShortTTLModules hook

* use it to load wikia.ext.abtesting module
* call it in WikiaMobile skin as well
InstantGlobals: initial commit
InstantGlobals: load it in wikia/DefaultSettings.php
InstantGlobals: add a short description
InstantGlobals: emit wgAmazonDirectTargetedBuyCountries
InstantGlobals: Oasis only for now
AdEngine: wgHighValueCountries to be exposed in JS by InstantGlobals
AdEngine: wgAmazonDirectTargetedBuyCountries to be exposed in JS by InstantGlobals
InstantGlobals: expose Wikia.InstantGlobals
Typo and some docs
InstantGlobals: follow the naming convention
Revert: 6e02763, 4b71040, a418bfb
Introduced 'wikia.instantGlobals' require module
ADEN-1152 Use Wikia.InstantGlobals for high value counties and Amazon countries
Introduced InstantGlobalsGetVariables hook
Removed $wgHighValueCountriesDefault and $wgAmazonDirectTargetedBuyCountriesDefault
'wikia.instantGlobals' module return always an object
InstantGlobals: allow overriding the values by a wg variable (useful for devbox)
InstantGlobals: run stylize.php
Merge pull request #3580 from Wikia/instant-globals

Implement Instant globals