Workaround for Firefox 0S 2.0 which has getFeature(), not hasFeature() (bug 1097424)
Apply feature detection profile to feed APIs (bug 1103169)
remove extra top margin on feed app preview tiles (bug 1109232)
Persist user settings between refresh (bug 1107484)
add smooth scrolling to mobile nav (bug 1109260, bug 1059002)