'cb' -> 'callback'
Merge pull request #56 from adrianparsons/master

call a callback a callback
Added ftrim() command to the client

This command sets a reference of the horizontal plane
for the drone internal control system.

Relates to #27
vidionDetect -> oriantationAngle is a float32
Merge pull request #57 from eschnou/fix_vidiondetect

vidionDetect -> oriantationAngle is a float32
Merge pull request #54 from eschnou/feature_ftrim

Added ftrim() command to the client.