Working prototype with CellTowerHandler handling cell signal and tower information updates.

Changes done:
* renamed the package 
* renamed the project in Eclipse (you may want to re-import the project from scratch after merging, Eclipse might get confused)
* added the ability for the CellTowerHandler to process cell updates from Telephony manager in the background. 

You could add ability for client to request information from the Service, if you want to force the updates to happen at predefined time intervals. However, it might be more appropriate to write reactive code and plan for callbacks to be driving the application state changes (this might be more robust).