Update ports.h
added drivetrain object and updated ports
Merge pull request #24 from swarage/master

added drivetrain object and updated ports
Merge pull request #25 from ZackAlfakir/master

Added arm code. Need Sensors
we're testing this code on the robot
Merge pull request #26 from swarage/master

we're testing this code on the robot
added arm to joystick registry
Merge pull request #28 from swarage/master

added arm to joystick registry and moved things to registries
fixed minor things
Merge pull request #29 from swarage/master

fixed minor things
wow many ports very drivetrain constructor wow