CHECKPOINT: Can now discover and read bluetooth characteristics with Samsung Galaxy SIII running  Android 4.1
Committing addition of constants that represent the agreed upon Bluetooth Low Energy standard labels for different types of services and data (e.g. walking speed, datetime, etc.).
Constant values come from bluetooth.org
Committing stabilization of connecting and disconnecting- now connecting and disconnecting more than once doesn't crash the application. Changes are there to enforce a singleton design pattern: only 1 BLE connection object is allowed to exist at once.