drivers/cc110x: Made address format in debug output consistent

cpu/kinetis: Refactor LPTMR timer implementation

shell_commands/ping6: Fixed bug in calculation of average round trip time

gnrc_pktdump: print rest of snip as hex if available

sys/trickle: document time interval unit 'ms'

The average rout trip time has been to low in case packets were lost, as lost
packets were treated as if that had an RTT of 0.

Currently, `gnrc_pktdump` only prints the header part of a snip.
However, if the snip wasn't parsed yet by the corresponding GNRC
module (or the module doesn't exist because the node is e.g. just a
forwarder), additional data might not be printed.

This makes it hard to analyze the data properly (sometimes you not only
want to know where the IPv6 packet is supposed to go, you also want to
know what's in it). So this just prints the rest of the snip as a hex
dump.

Unit is milliseconds as said here:

https://github.com/RIOT-OS/RIOT/pull/9145#discussion_r188861183

uncrustify: add check for no newline at end of file

kinetis: Refactor PIT timer driver implementation

uncrustify add empty body brackets support

sys/cb_mux: Callback multiplexer

boards/msbiot: on-board buttons and saul integration

drivers: Various minor improvments of the cc110x driver

makefiles/tools: use RIOTTOOLS variable

boards: use RIOTTOOLS variable

net/emcute: use correct number of retries

syncsend() is used also for the initial packet, so resending
while (retries <= EMCUTE_N_RETRY) is the correct behavior.

core/debug: fix debug.h use within ISRs

The newlib-nano include directory can be named either newlib-nano or
nano, so we should make sure it is added in both cases.

cpu: efm32: fix for cpp support.

uuid: Initial import of RFC4122 UUID functions

doc: fix quick guide command order

sys/uart_stdio: remove unused rx_cb from header

git checkout can only work if you've already changed to RIOT folder.

Lua support - initial PR