pios_mutex: add implementation
all fw makefiles: add pios_mutex.c
pios_com: use pios_semaphore and pios_mutex
pios_semaphore: add workaround for sim_posix
all pios_board.c: fixed uninitialized usage by reordering init sequence
Quanton: disable invert on UART2 when not using SBus

We should actively disable this inverter when not being
used.
Merge pull request #1246 from lilvinz/fix_uninit_usage

all pios_board.c: fixed uninitialized usage by reordering init sequence
pios_ms5611: use pios_semaphore
pios_ms5611_spi: use pios_semaphore
flight/uavtalk: use pios_semaphore
alarms: use pios_mutex, was recursive mutex before
flight/uavtalk: use pios_recursive_mutex
eventdispatcher: use pios_recursive_mutex
uavobjectmanager: use pios_recursive_mutex
taskmonitor: use pios_mutex, was recursive mutex before
pios_lsm303: use pios_semaphore, was mutex before
pios_mpu9150: use pios_semaphore
pios_rfm22b: use pios_semaphore
pios_hmc5983: use pios_semaphore
pios_hmc5983: fixed resource leak on allocation