BOARD::GetBoundingBox() now directly calls BOARD::ComputeBoundingBox()
and there is a new method BOARD::GetBoardEdgesBoundingBox() used for
call sites that needed to use ComputeBoundingBox( true ) in the past.
This allows COMMON_TOOLS to implement ZoomFitScreen without knowledge
of the BOARD class.
Now footprints, after loaded by reading a netlist are grouped by sheets by the footprints spread function, and the grouping is better.
Rename 2 files. Fix minor issues. Clean code