HAL_Linux: switched to pthread based scheduling
DataFlash: enabled DataFlash_File for Linux
build: added -lpthread and SKETCHNAME in build
git: ignore ~ files
Plane: use DataFlash_File on Linux
AP_HAL: make timed processes take void *argument

this allows the class to be passed in, meaning that drivers that use
register_timer_process() and register_io_process() don't need to use
static members. That results in simpler, easier to read code
HAL_AVR: updates for new scheduler API
HAL_AVR_SITL: updates for new scheduler API
HAL_Empty: updates for new scheduler API
HAL_FLYMAPLE: updates for new scheduler API
HAL_Linux: update for new scheduler API
HAL_PX4: update for new scheduler API
AP_InertialSensor: use new scheduler API
AP_OpticalFlow: use new scheduler API
DataFlash: use new scheduler API
AP_ADC: use new scheduler API
AP_Baro: use new scheduler API
Rover: use new scheduler API
Copter: use new scheduler API
Plane: use new scheduler API