Add "Off" in MainUI menu button and other suggestions.

[Rix-97]

1. Add "Off" in MainUI menu button.
2. Bring back brightness shortcut in MainUI menu. (for example if long press menu button in MainUI options are "Off") FIXED
3. Fix accented letters in Activity Tracker. (If possible)
4. Add a setting to fast overlock the cpu in 100hz increments up to 1600 to avoid problems with the mini non plus. (experts mm+ users could then increase it even further like 1700 or 1800 by editing the file manually)