Cell-id - Issue #30

I am not 100% sure the proposal is "optimal" (info is slightly conflicting), but it should be better than it is now.
This will invalidate the saved cell id lists, so it should be done before released on Google Play.

I suggest the following changes:
* Remove Psc for GsmCellLocation (even if it could be unique for some Wcdma cells in some phones, it does not identify)
* Switch order of Lac and Cid for GsmCellLocation
* Handle getCid, getCi() == -1 as an error (reactivate isError())
* Add Tac() for Lte: http://people.csail.mit.edu/bkph/cellular_repeater_numerology.shtml
* Mnc/Mcc can be retrieved for CellLocation, skipping for now
* While it would be nice to get the sector (antenna), the rles differ. Only present for LTE