KiCad cannot have more than one board/project open, so disallow
the Python APIs for loading additional boards when the frame is
present. Inherit the SETTINGS_MANAGER from the frame when present
instead of creating a new one that won't have the loaded project.
Currently there is pcbnew.ExportSpecctraDSN() but it needs a pcbnew
frame set which makes it unusable outside of the scripting window or a
plugin.
This refactors actual exporting logic into separate helper and adds an
overload to ExportSpecctraDSN(board, filename) that doesn't need pcbnew
window.
Jon Evans
qu1ck
Wayne Stambaugh
Seth Hillbrand