cpu/stm32f1: fix i2c master read for N>2 bytes

This fixes reading more than 2 bytes from the slave device.
In the current implementation the last byte was not read from
data register and the termination sequence buggy.
cpu/stm32f1: fix i2c read for N=2 bytes
core: make sched_runqueue public

Reverting b604832, because thread_yield() needs to access this
information.
core: move thread_yield*() to thread.[ch]

Although it might conceptionally rather belong to the scheduler, the
yield functions are prefixed with thread_ and thus, belong there.
rpl_udp: add non-routing hosts to example
trickle: increase stacksize for timer thread

printf is used in this thread
drivers/at86rf231: refactoring of the at86rf231 radio driver

* deploy extended operation mode
* cleanup
* implement netdev 802154.h interface
netdev/802154: suppress cppcheck warnings in 802154.h

Suppress cppcheck warnings of class unusedStructMember because
this interface is not used yet. Remove these comments once it
is used.
Revert "boards: introduced a HAS_RADIO define"

This reverts commit 4238f404299528655ef0526bb33a51a1f34dfffb.
config: use FEATURE_PROVIDED instead of HAS_RADIO
sys: lib: introduce ringbuffer_remove()

This commit adds a function that deletes n elements from the ringbuffer
without actually writing them somewhere.
Merge pull request #1649 from kaspar030/ringbuffer_remove

sys: lib: introduce ringbuffer_remove()
Merge pull request #1911 from OlegHahm/fix_trickle_timer_stacksize

trickle: fix timer stacksize
Merge pull request #1885 from OlegHahm/thread_yield_higher_cleanup

core: thread_yield_higher cleanup
Merge pull request #1872 from thomaseichinger/stm32f1-i2c-multibyte-fix

cpu/stm32f1: fix i2c master read for N=2 and N>2 bytes
Merge pull request #1915 from OlegHahm/replace_has_radio_by_feature

make: replace has radio by feature
Merge pull request #1903 from authmillenon/rpl_udp_non_routing

rpl_udp: add non-routing hosts to example
yunjia: rm unused file
Merge pull request #1916 from mehlis/yunjia-rm-unused-file

yunjia: rm unused file
lint: fix unassignedVariable warnings in stm32f1