Fix comments
unittests: Simplify module-wise rebuild
cpu/nrf51822: added driver to get CPUID
test/periph_cpuid: renamed cpuid test application
Merge pull request #1620 from authmillenon/unittests-easy

unittests: Simplify module-wise rebuild
cpu: atmega_common: Initial import
cpu: atmega2560: Initial import
board: arduino-mega2560: Initial import
tests: blacklist failing test on arduino-mega2560
sys: inet_pton: conditional include for atmega2560

    include sys/types.h conditionally for atmega2560
    Without this change test/unittests fails to build due to a missing
    declaration of ssize_t
Merge pull request #1420 from N8Fear/initial_import_arduino_mega2560

board: cpu: Initial import of the Arduino Mega2560
Merge pull request #1621 from haukepetersen/add_nrf_cpuid

cpu/nrf51822: added cpuid driver
Merge pull request #1616 from krf/fix-warnings

Fix comment
boards: initial import of yunjia-nrf51822 board
cpu/nrf51822: some fixes and clean up

- enabled power for uart and timer
- outsourced timer config values to periph_conf.h
- made linkerscript better readable
- adjusted default stack-sizes
- let RED_LED blink on hard_fault
board/pca1000x: small fixes to periph_conf.h files
tests/examples: blacklisted yunjia-nrf51822