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
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``...
Merge pull request #1619 from rousselk/msp430-hwtimer-16bit

Only use 16 significative bits for MSP430 hwtimers
tests: remove do-while(0) blocks for netdev tests or comment on them