Revert "replaced all wfMessage()->escaped() with wfMessage()->plain() because of performance reasons"

This reverts commit 8401c5aa4cf8260c38c253843931e5447a006f32.
CONN-178 added clicktracking for clicks on wikia terms of use
Fixed scrollable background on IE 11
manually merged CONN-10-updated and resolved conflict in extensions/wikia/UserLogin/js/UserLoginFacebook.js