* Add footprint methods to PCB_IO.
* Add FP_CACHE and FP_CACHE_ITEM for handling new footprint library design.
* Add code to save legacy libraries in new format.
* Change behavior of BOARD_ITEM::GetLayerName() to return the default layer
name when the item does not have a BOARD as a parent.
* Minor changes to the module output formatter when writing to module library
files (no BOARD as parent).
* Add new (and some that I forgot along the way) CMake flags to
EDA_BASE_FRAME::CopyVersionInfoToClipboard().
* Add -Wno-narrowing to GCC flags to stop GCC 4.7 from complaining about
a conversion from int to unsigned in the Boost polygon library.
* Add INPUT_STREAM_READER to richio.cpp to allow using any object derived
from wxInputStream as a LINE_READER (needs to be validated).
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.