The boat simulator now properly sets the newData attribute on the GPS bus. Necessary for upcoming controller changes.
Added a GPS slew rate filter to the GPS input to the controller. This does a zero-order hold on incoming GPS data if it changes too quickly. This will take care of resets or large GPS jumps without requiring a change to the rest of the system.

I should really add an estimator for the current vessel heading, though, that factors in the rudder angle to use something better than maintaining last course-over-ground. I don't think that's a critical requirement for the next launch though. I think things are certainly shaping up here.
Removed unnecessary ThrottleCommand/RudderCommand structs from MATLAB.
Also fixed bug with manual control where a value of 0 mapped into a commanded current of 150. Now reverse can also be full speed, instead of being capped at 70%.