Draft: Launch gerbview/pl_editor/pcb_calc as frames from project manager
Launching as frames instead of as standalone applications allows them to get the most recent common settings and also to run them from the build directory.
It would be good if a Windows dev can give this a test to make sure the kifaces are properly located there (I think it should work).
Related to #1939 (closed) and !82.
Edited by Ian McInerney