Streamlined ar drone interface, removed a lot of old cruft, preparing for generic multirotor control

Switch back from max performance to size as the default optimization level.  Individual modules can still override this if they need to.

Syntax change to improve readability; output scalers are now labelled O: instead of looking like control scalers.

Make mixer terminology more consistent; mixer inputs are 'controls'.

Added manual control abstraction layer, reworked sensors and ardrone_control apps to use it instead of direct RC channels

Back out the last STM32 DMA priority change.  It is not necessary; just dropping the SD frequency was sufficient

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@5021 7fd9a85b-ad96-42d3-883c-3090e2eb8679

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@5020 7fd9a85b-ad96-42d3-883c-3090e2eb8679

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@5019 7fd9a85b-ad96-42d3-883c-3090e2eb8679

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@5018 7fd9a85b-ad96-42d3-883c-3090e2eb8679

Now the mixer is a C++ library that can be fairly easily bolted into an output driver to provide mixing services.

Teach the FMU driver how to use it as an example.  More testing is still required.

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@5017 7fd9a85b-ad96-42d3-883c-3090e2eb8679

Drop the X and + rotor mixers.  We can't do multirotor mixing statically like that, as there is no mechanism for dealing with channel saturation.

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@5016 7fd9a85b-ad96-42d3-883c-3090e2eb8679

Update documentation to describe customization of NSH; Add the framework for a LPC43xx USB0 driver (not functional)

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@5015 7fd9a85b-ad96-42d3-883c-3090e2eb8679

Completed calibration state machine, calibration state now propagating to sensor, scale calibration soon

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@5014 7fd9a85b-ad96-42d3-883c-3090e2eb8679

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@5013 7fd9a85b-ad96-42d3-883c-3090e2eb8679

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@5012 7fd9a85b-ad96-42d3-883c-3090e2eb8679