- stub out nRF8001 utility files on nRF51
- initial support for RedBearLab nRF51822 boards

- advertisement/scan data
- connect/disconnect
- services
- read/write characteristics
- mod sketches for nRF51
- cleanup, notify/indicate characteristic support, 0x2902 + 0x2904 descriptor support
- support other types of descriptors
- cleanup and BLEDevice abstraction
- untested SAM + SAMD support
Merge branch 'RBL_nRF51822'

Conflicts:
	nRF8001.cpp