Driver for a Goldcut cutting plotter 

It was written to support a Goldcut ABH 721 [Refine MH721, Jinka JK721]
Speed and pressure of the devices cannot be software-controlled. This is done on the device.

These devices are simple HPGL plotters, thus the driver should support many more devices.
Maybe helpful with t-oster/VisiCut#256

added travel feedrate setting

Marlin driver update

fix for "Underlying input stream returned zero bytes"

Marlin driver

can be adjusted if user is finding they constantly get `java.io.IOException: Underlying input stream returned zero bytes `

timeout would cause the following error: "java.io.IOException: Underlying input stream returned zero bytes"