Add some progress while processing an image.

Proessing a largish image (like the Aligment2.png) takes quite a
while on a slower machine. This causes the progress output to be
displayed on the GUI.
Merge pull request #23 from trent-waddington/develop

Update port list periodically and report connection errors.
Merge pull request #24 from trent-waddington/develop

Assorted housekeeping and testing
Merge pull request #25 from trent-waddington/develop

Add some helpful information about required libs.
merge dhylands-process-progress
Merge pull request #26 from trent-waddington/develop

Add some help for linux users.
Add note.
Merge branch 'develop' of https://github.com/CartesianCo/argentum-control into develop
Merge remote-tracking branch 'upstream/develop' into develop