samr21: implemented transceiver via spi, gpio changes
board/mbed_lpc1768 changed the serial device to UART0
                   -> enables USB/serial communication
Revert "tests: don't build test/libfixmath on Travis CI"

This reverts commit f061d0214ebb788b3262b312a80323f5a1473d27.
periph/rtc: move struct tm note to the top

The remark is valid for the whole interface, not just `rtc_get_time`.
Merge pull request #2201 from BytesGalore/mbed_lpc1768_uartUSB

board/mbed_lpc1768 changed the serial device to UART0
Merge pull request #2193 from LudwigOrtmann/libfixmath-test

Revert "tests: don't build test/libfixmath on Travis CI"
Merge pull request #2205 from LudwigOrtmann/periph-rtc-doc

periph/rtc: move struct tm note to the top
exclude ``ipv6_iface_set_routing_provider()`` from ``#ifdef MODULE_RPL`` so that other routing protocols can use it too.
Merge pull request #1997 from Troels51/samr21-transceiver-port

samr21: implemention of transceiver via spi
add parentheses to ENABLE_DEBUG in CBOR_NO_PRINT
Merge pull request #2208 from Lotterleben/cbor_add_define_parentheses

add parentheses to ENABLE_DEBUG in CBOR_NO_PRINT
Make hwtimer_spin() work even with interrupts disabled
by using only 16 significative bits on MSP430 hardware timers
Reduce variable scope in init function
fix typos in ip.h, mac.h, ndp.h and types.h
Merge pull request #2210 from Lotterleben/fix_sixlowpan_typos

fix typos in ip.h, mac.h, ndp.h and types.h
samr21: implemented 32 bit hwtimer
drivers/srf08: initial import of the updated ultrasonic driver
Merge pull request #2179 from PeterKietzmann/adapt_srf08_ultrasonic_driver

drivers/srf08: improved and adapted ultrasonic ranger driver to general i2c interface
Merge pull request #1998 from Troels51/samr21-hwtimer-fix

samr21: 32 hwtimer
Merge pull request #2212 from Lotterleben/fix_ipv6_iface_set_routing_provider

exclude ``ipv6_iface_set_routing_provider()`` from ``#ifdef MODULE_RPL``...