Added Firefox OS "detection"

Which is really to know when *not* to apply desktop styles.
Auto-apply "mnml" theme for iOS 7

RegEx based on
https://github.com/cheeaun/hackerweb/blob/8a9ed45ca4a0bab91ea500abd20bc4
1cd08dbc52/index.html#L153 :) (I can't get seem to click into regex!)
Slight changes to "mnml" styles

More in line with Mobile Safari's 7 colors.
Bumped appcache