all pios_irq: add PIOS_IRQ_GetInISR() method
GCS/Uploader: set boot timeout to three second

This is the maximum time it should take with the new
bootloader. The old one may still take longer.
Merge pull request #1338 from peabody124/uploader_boot_timeout

GCS/Uploader: set boot timeout to 3 seconds
pios_com: ensure proper usage of Semaphore_Give depending on context
Merge pull request #1335 from lilvinz/pios_com_isr

pios_com: separate isr and non-isr callbacks
ChibiOS: Pristine import of v2.6.6
ChibiOS: fix GPIOv2 conflict with st libs GPIO_TypeDef
ChibiOS: remove CMSIS arm_math.h to prevent conflict
ChibiOS: disable stm32f30x usb irq relocation for legacy compatibility
pios_semaphore: fix mismatched comment
pios_semaphore: add ChibiOS implementation
pios_semaphore: fix simulation exception
pios_mutex: add ChibiOS implementation
pios_thread: add ChibiOS implementation
pios_queue: 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/stm32f4xx: add pios_chibios_transition_priv.h