Don't ask to save model when SketchUp does autosave

[Peter Ellis]

SketchUp defaults to autosave the SKP file periodically. The problem is that Euclid also tries to save the EnergyPlus model when SketchUp autosaves. This can be annoying. Instead it would be better to not trigger Euclid to save unless there is actual EnergyPlus content, i.e., it's a Euclid model. Or another option is to completely disconnect Euclid's save from SketchUp's save.

[Peter Ellis]

Fixed with commit 9fa2c55. This changes the process to never associate the .idf file with the .skp file in the first place. It also adds a warning that is shown when the user tries to save the .skp file to remind them to use Euclid's own Save and Open commands--along with a note that suggests turning off autosave.