drivers: Initial import of SPI low-level driver IF
drivers: fixes to the SPI low-level interface
driver: updated SPI driver interface
[SQUASH ME] added fixed speed values
[SQUASH ME] removed UNDEFINED from device list
[SQUASH ME] fixed signature of spi_transfer_reg()
[SQUASH ME] added begin_transaction, fixed doc
.astylerc: Respect max code line length of 100
Merge pull request #1536 from krf/fix-astylerc

.astylerc: Respect max code line length of 100
cpu/nrf51822: squash added support for nrf51822 cpu
boards/pca10000: squash added support for Nordic Dev Kit p1
boards/pca10005: squash added Support for Nordic Dev Kit p2
Merge pull request #1498 from fukuehl/nrf51822

cpu/board: added support for nrf51822
Merge pull request #1311 from haukepetersen/add_driver_spi_if

drivers: Initial import of SPI low-level driver IF
boards: fixup for pyterm renaming
Merge pull request #1543 from LudwigOrtmann/pyterm-fixup

boards: fixup for pyterm renaming
doc: fix spelling in core/include
Merge pull request #1545 from LudwigOrtmann/spellingbee

doc: fix spelling in core/include
core/queue: queue -> priority_queue

Rename queue to priority queue, because that's what it is.
core/priority_queue: add dynamic initializers

- priority_queue_init
- priority_queue_node_init