Added the ability to apply PX4 specific patches to Nuttx
 At the moment this entails adding NuttX/nuttx/arch/arm/include/math.h
Updated configs
Fixed typos
better nameing and direction
repointed NuttX submodule
Update configs with latest upstream setting
Updated Configs to use the new handshake thresholds
Update .gitmodules

Back to PX4
Merged David Sidranes WIP
Merge branch 'nuttx_bringup_redux' of github.com:PX4-Works/Firmware into nuttx_bringup