Major refactoring of SerialCommunicator and MainForm. Attempting to simplify
the SerialCommunicator (i.e. it shouldn't know anything about Grbl) and to
bring all control logic into a new control class. When finished the GUI and
the backend should be completely separate and I will be able to make a CLI
front end.
Continuing to pull logic out of SerialCommunicator and MainWindow.
Continuing to pull logic out of SerialCommunicator. Issue# 48
Status polling moved to controller. Issue# 48