STL Queuing Support

[D1plo1d]

Ideas

• The stl preview screen could be embedded in a pop up when you add a stl to the queue (concurrently generating GCode so as not to block adding more STLs to the build queue)
• GCode => STL conversions could be done in a second thread or set of threads to optimize for multi-core machines and allow concurancy with the ui.
• How to deal with concurrent printing and gcode compilation so we don't block the print?
  • wait until the first GCode is generated before printing the queue or
  • estimate if GCode generation is expected to be longer then print time and if so delay the print until GCode generation is not the limiting factor.

[D1plo1d]

No STL preview yet but STLs can be queued initially and will auto-compile to gcode based on machines.xml driver material settings.