pios/common: added pios_freertos_transition
pios/stm32f4xx: added pios_freertos_transition_priv.h
pios/stm32f30x: added support for ChibiOS
ChibiOS: disable stm32f30x usb irq relocation for legacy compatibility
pios_mpu6000: use worker thread
pios_l3gd20: use worker thread
fw_flyingf3: switch to ChibiOS
fw_quanton: switch to ChibiOS
fw_sparky: switch to ChibiOS
fw_revomini: switch to ChibiOS