* Refresh the view only when changes are made in the caller frame.
* Allows recreate a new instances when try to open the 3D view from a frame taht is not the initial caller
* Remove duplicate code in kicad frames.
While we already cache the loaded footprint files, parsing said files
into the list is also time-intensive. Since the FOOTPRINT_LIST is
already hash-stamped against the current timestamps of the files that
make up the list, sharing a single copy of the list is quite
straight-forward.
Fixes a bunch of errors:
- libedit and libbrowser would zoom to bounding box but centre on canvas
- libedit, libbrowser and gerbview didn’t take the scroll bars into account
- pcbnew didn’t take scroll bars into account or apply the 10% margin
- appending a board file would re-centre, but not re-zoom
Fixes: lp:1504302
* https://bugs.launchpad.net/kicad/+bug/1504302
jean-pierre charras
Jeff Young
Maciej Suminski
Michael