The attached patch makes the following changes to import DXF:
1. correctly implements scaling based on DXF $INSUNITS -
at least where INSUNITS is sensible. I ignore units like miles,
gigameters, AU, lightyear, parsec ...
2. correctly implements LWPolylines, adding an ARC segment
rather than a line segment when bulge != 0. A number of users
have been complaining about getting the wrong board shape
(chamfered corners rather than rounded corners) on DXF Import,
now they shouldn't complain.
- DIALOG_DXF_IMPORT works with PCB_BASE_FRAME instead of PCB_EDIT_FRAME
- imported items are not immediately added to a BOARD
- imported items are held in a list, instead of vector
- imported items are instantly visible in GAL view
- added DIALOG_DXF_IMPORT::GetImportedItems()
- code formatting