Tracks should be loaded in the same order as they were saved, no exceptions.
This is for the version control system user.
But even with this objective now implemented in LEGACY_PLUGIN, the TRACKS
are still going through a food processor after they are loaded, and the poor
version control system user has no relief, even with this patch.
TRACKS are always modified after being loaded, and I think this needs to be fixed still.
* Save dialog now supports saving boards to new file format.
* Add CMake option to build s-expression file save.
* Add check to main CMakeList.txt file to make sure nanometers are
enables when the new file format is built.
* Minor tweaks to object format functions for improved output.
* Rename kicad_plugin.h/cpp to legacy_plugin.h/cpp.