* Add s-expression Format() function to all objects derived from
  BOARD_ITEM.
* Add s-expression Format() function to base objects as required.
* Add functions to convert coordinates from base internal units
  (nanometers) to millimeter string for writing to s-expression
  file.
* Add temporary dummy conversion functions to prevent link errors
  until schematic and board object and action code can be separated
  into DSO/DLL.
* Add CMake build option to build Pcbnew with nanometer internal
  units.

other minor fixes.

Some code restyling: VECTOR_PCB is an array. Cleanup uncontrolled definitions of abs, max, etc. max is now overloaded function and MAX is a macro.

BOOST POLYGON is always used in zone filling functions.
Kbool is still in use in other calculations.

Fix minor other issues.
Remove unused files.

Cosmetic enhancements. Eeschema: in libedit the Value Field is n more editable in the field editor dialog (due to recent changes in library code)

* Break classes_body_item.cpp(.h) into more reasonable size bites.
* Rename classes_body_item.cpp(.h) to lib_draw_item.cpp(.h)
* Fix some unsatisfied header file dependencies.
* Add stubs to component library draw item base classe to handle editing
  internally.
* Lots of code cleaning.

Added boost::polygon (experimental)
Added experimental zone fill calculations with boost::polygon
Added patches from Yury Khalyavin

fixed bug 603481. Better bitmap2component look. fixed some locate problems for footprints using polygons (mainly created by bitmap2component)

Added an experimental tool to create logos from .bmp bitmaps. Added Potrace library to convert bitmaps to polygons