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