Getting the print queue api working with the printer, adding a job progress panel to inspector and adding job_finished and job_started events.

While neither PCB milling nor comments in parentheses are
part of the innermost core or RepRap printing, they happen
and should be handled gracefully.

The projectlayer file dialog now accepts files with the extension
*.3dlp.zip and will extract the contents to a temporary folder. It then
finds any *.bmp files and adds them as a set of layers.

Notes:
- Offset works, but currently scale does not affect the bmp files.
- *.3dlp.zip was chosen to mark the file as being for dlp based
resin printers, but also processable by regular archive programs.
- Have also introduced a checkbox to let the user decide to display
  fullscreen or not, as they may want the window dragged to a second
  output.