Improve dialog layout and fix UI policy issues with all of the dialog
boxes in the Gerbview and Pcbnew code paths.
Updated the use of component to footprint where appropriate.
SHAPE_POLY_SET: fix crash in VertexCount when it is a empty poly set, or when params are incorrect.
minor other fixes:
warning in degug mode in dialog_dxf_import_base.cpp
pcb_painter.cpp: remove a useless debug line.