2.3-beta4: Merge pull request #189 from AltBeacon/workaround-500-alarm-limit

Changes since 2.2:

Features:

Support for Gatt-based beacons and interleaved frames
Optionally allow tracking multiple beacons with the same identifiers, distinguishing with the mac address.
Filter out invalid RSSI values of 127 for distance calculations
Identifier class now supports conversion to/from the UUID class.
Optionally allow using an ArmaRssiFilter for faster distance calculation convergence.

Bug Fixes:

Workaround for 500 alarm limit on Samsung devices.
Fix NPE in scanning for beacons on Lollipop in the emulator
Restart scanning after app is killed due to memory pressure
Protect against crashes when falling behind on scans
Protect against null pointer exceptions in race conditions
Protect against crash when stopping advertising with bluetooth turned off
Stop BLE scanning after stopping ranging of the last region