gnrc_sixlowpan_nd: initial import of host behavior of 6LoWPAN-ND

cpu/stm32f4: fixed typo in prescaler for timer1

rpl: RPL Instance ID 0 must be allowed

rpl: RFC6550 states that you should use PadN instead of multiple Pad1 bytes

cpu/stm32f3: disable debug in GPIO driver

Arduino-mega2560 GPIO implementation

gnrc: ipv6: netif: obey naming conventions

sys: xtimer: fix xtimer_usleep_until doxygen

sys: shell: work around inlined putchar

cpu/stm32f1: added stm32f103c8 linkerscript

Makefile.iotlab: accept custom resource id list for experiment-cli

tests: xtimer_usleep_until: fix diff calculation

drivers/srf02: some optimizations

- switched test to xtimer
- adapted to interface changes

- switched to use xtimer
- simplified interface slightly
- optimized reading of results
- some style cleanups
- updated the documentation

universal_addresses: configure sizes according to the used modules

cpu/native: adjusted stacksizes

drivers: add driver for encx24j600 ethernet chips

xtimer_usleep_until's internal logic has changed, always setting
&last_wakeup to the expected instead of real value.
In order to make this test output valid values, this commit adapts it.

misc timer fixes

sys: remove uart0