huge update: added feedrate for jogging, updated and improved the command queue, fixed bug where machine coords would be lost, added pause/unpause, added clear queue, improved console output, updated rPi image to include latest node libs and packages (huge s.io perf boost), automatically selects serial port if only 1, jogging no longer requires G91 to be set first, greatly improved working and machine coords UI with tabbed interface, change license to AGPL v3, added gcode visualizer, added min/max/total dimensions for object/gcode