Kicad manager: shows now svg files in tree files.
Pcbnew: fix incorrect printing (board out of page) when creating drill map in postscript format ( noticeable mainly for small boards)
* Move board item object Format() functions into PCB_IO object.
* Change file format to use layer names instead of numbers.
* Change file extension to kicad_pcb.
* 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.
jean-pierre charras
Dick Hollenbeck
Wayne Stambaugh