Initial gCodeViewer (http://github.com/hudbrog/gCodeViewer) integration
Initial implementation of autoupdate gcodeview on status from server
Auto-load file on connect; some refactoring
Bug: octoprint deleted all commented lines, now gcodevisualizer deletes them too so the line numbers match
gCodeVisualizer can be enabled as a feature in config now (enabled by
default)
Some cleanup from initial integration: removed separate icon for viewing gcode