Add ability to run "manual controls"

[meganandd]

Allow carriage and rotor axes to be operated manually and independently.

This is probably like "shakedown run" functionality, except that I would want there to be a way to turn the rotor on to a given speed without necessarily moving the carriage. May be useful for testing and debugging.

Could be a three-parameter interface: rotor speed, carriage speed, TSR. You pick two, and it defines the other. Then you can perform a run of that given set of operating conditions. Ideally, a carriage speed of zero would be an acceptable argument. I'm not sure how long it would run (indefinitely, until stopped?) because the carriage would never reach travel limits.

Similarly, one may want to run the carriage with the rotor stopped. (This could be performed in Tow. Can Tow run at the same time as TurbineDAQ? Would be nice to have the ability to run carriage tows from within TurbineDAQ