Initialize GPIOs for EXPOSURE and STANDBY lines of the camera

This keeps these data lines from floating and causing dark lines in the image
Merge pull request #13 from jhiesey/master

Initialize GPIOs for EXPOSURE and STANDBY lines of the camera
Fix compile warning in MAVLink conversions
Implement reboot command end-to-end
Merge pull request #15 from PX4/reboot

Reboot
adjusted exposure time to max 64 lines, reduced flow calculation to be performed at 5x5 different positions within 64x64 pixel image, minimized horizontal blanking time to achieve 400Hz update rate
Merge branch 'master' into beta