Initial check-in of rocket_tracks.
Modified accumulator divisor/multiplier to improve feedback stability
Added cmd_freeze and cmd_unfreeze functions
Merge branch 'master' of https://github.com/psas/stm32 into rocket_tracks
Scaled PID feedback calculations for 12-bit ADC's
Merge branch 'master' of https://github.com/psas/stm32 into rocket_tracks
Merge branch 'master' of https://github.com/psas/stm32 into rocket_tracks
Modified to reflect changes in ChibiOS/usbdetail file structure
New flight-rnh compiler + other features

Added ethernet to flight-rnh
Added first attempt at sleep mode from ACOK
Merge branch 'master' of github.com:psas/stm32
Merge branch 'master' of https://github.com/psas/stm32 into rocket_tracks
Working port to STM32E407 board complete.
Moved to new file structure.
MPU and MPL downsample rates added to sdclog thread
Merged PWM, pwm_exp, pwm_mod into pwm

Cleaned up functionality to make it more specific to just a demo
of the pwm.
Merge branch 'master' of github.com:psas/stm32
Updated some readmes
Made readme names consistent and match the style in other repos
Added makefile that builds and cleans all projects
Wrappers around f_write and f_read