Stabilization: fix small typo for yaw autotuning

This prevented the yaw gain autoadjusting, but was
always going to the max level.
Sim Posix: use -D USE_POSIX for consitency with OSX
PiOS Semphore: fix for SIM_OSX

Sim has no ISR methods. This maps them to the normal
non-ISR methods for simulation.
Merge pull request #1273 from peabody124/stabilization_useless_if

Stabilization: fix small typo for yaw autotuning
Merge pull request #1253 from lilvinz/pios_thread

Pios thread
ChibiOS: Pristine import of v2.6.3
ChibiOS: fix GPIOv2 conflict with st libs GPIO_TypeDef
pios_semaphore: add ChibiOS implementation
pios_mutex: add ChibiOS implementation
pios_thread: add ChibiOS implementation
pios_com: add support for ChibiOS
pios/common: add support for ChibiOS
GenericI2CSensor/i2c_vm: add support for ChibiOS
System: add support for ChibiOS
pios/common: add pios_freertos_transition
pios/stm32f4xx: add pios_freertos_transition_priv.h
pios/stm32f4xx: add support for ChibiOS
pios/stm32f30x: add support for ChibiOS
ChibiOS: disable stm32f30x usb irq relocation for legacy compatibility
all flight: use pios_heap