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

kinetis: GPIO: Enable the correct IRQn on CM0+

xtimer_now64_continuity: Enable test run on CI

pkg: ndn-riot: initial import of ndn-riot as a package

- Lua print() function is only supported function
- Lua script is parsed at compile time and run in example

- download of v5.3.4 of Lua from git
- building using RIOT build system
- patched to remove the need for _times and _link to be
provided to Lua via newlib.

boards: add Ublox C030-U201

pkg/tinycbor: Initial import

net/gnrc/rpl: fix doxygen grouping

drivers/periph: add basic API to read/write data to EEPROM

tests/xtimer_now64: Start time measure after print

boards: use marketing name for stm32f769i-disco