Start on SDL output of nav data
Write labels on SDL window
Move all SDL drawing into its own class.  Add MYMETA files
Correct color handling
Add fake_nav to MANIFEST.  Remove unnecessary method
Use different font for output
Add note about font
Tweak parsing of floating point numbers in nav data
Output nav data numbers
Output roll/pitch lines
Draw circle for yaw
Draw battery
SDL output of yaw
Add documentation to SDLNavOutput.  Cleanup MANIFEST and ROADMAP.
Move around roadmap items