Copy SEGGER JLink scripts from boards/openmote to boards/cc2538dk.
boards/cc2538dk: Support flashing and debugging using the SEGGER JLink.
boards: fixeded UART defines for NRF borads

fixed for pca10000, pca10005, yunjia-51822
cpu/nrf51822: added interrupt mode to UART driver
tests/periph_uart_int: fixed formatting
boards: added missing STD_RX_BUFSIZE defines

added for:
- pca10000
- pca10005
- yunjia-nrf51822
cpu/nrf51822: made syscalls aware of uart0
config: use radio_address_t
config: moved from core to sys

There's no need to run config_load from core directly, can be done by
auto_init.
config: make members feature specific

Channel and address are only sensible for boards that actually have a
transceiver.
config: suppress cppcheck warnings
Merge pull request #1909 from locicontrols/cc2538dk-jlink

boards/cc2538dk: Support flashing and debugging using the SEGGER JLink.
Merge pull request #1900 from OlegHahm/config_radio_address_t

config: use radio_address_t in config_t
Merge pull request #1555 from haukepetersen/fix_nrf_uartdriver

cpu/nrf51822: added interrupt mode to UART driver
added board airfy beacon