Custom CSS tweaks for Firefox v4.1.7pre1-2

[GENERAL]

• Fx100+: workaround for ":-moz-lwtheme-darktext" and ":-moz-lwtheme-brighttext" removal

[General UI]

• (fix) Win7/8: 'page context menu > back, forward, reload and bookmarks button labels + icons'

[Buttons]

• (tweak) custom back/forward buttons appearance > connected to location bar

[Location Bar]

• (tweak) identity box colors
• (tweak) popup > hide 'Search with...' and 'Visit...' results