Experimental

Merge experimental changes since it appears to be stable enough (other than a few really crappy Android devices with a weird radio interface layer that deviates from the norm). Since no one with such devices wants to help me, they can just keep crashing in the mean time. 

Changes from stable:

- action bar sherlock for all
- options menu and preferences (keep screen on, different % readings, debug option)
- % readings (strict 3gpp readings and ones that look nicer compared to carrier readings)
- refactoring the code to be more forgiving and modular in the signal info layer (each type of signal is treated as a separate class with a parent class for shared functionality).