fix an issue created by commit 2954. Gerbview: display now an indicator of layers in use. minor code cleanup.

Kicad: bug fix: in zip project command: filenames are now quoted in command string. Previously if files have space or other exotic character in name, zip fails.

* Move schematic wire and bus break code into schematic screen object.
* Move schematic test for dangling ends into schematic screen object.
* Remove left over debugging output in schematic screen object.
* Remove unused file eeschema/cleanup.cpp.
* Fix bug in schematic line object hit test algorithm.
* Fix a string concatenation compile error added in r2752.
* Rename class WinEDA_BasicFrame to EDA_BASE_FRAME.
* Rename class WinEDA_DrawFrame to EDA_DRAW_FRAME.
* Rename class WinEDA_DrawPanel to EDA_DRAW_PANEL.

Minor cosmetic enhancements.
commint forgoten files in boost lib.

fixed bug 641982 (I hope)

removed in drawpanel an erroneous change (was made only for a test). drc code cleaning. cmakelist.txt changes in minizip.

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

Fixed compil warning under wxWidgets 2.9.1.
File beautification
Statring using wxTextEntryDialog instead of Get_Message (because Get_Message does not handle properly cancel option)

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

* Fix a minor problem with wxFileDialog to open a file that no longer
  exists in PCBNew.
* Make GerbView open file behavior the same as PCBNew.
* Remove redundant PCB file wild card definition.
* Add open file refactor task to the todo list.
* Fix some minor code formatting issues.

This patch applies on the very last svn  (r2402) and removes all
disfunctionnal python code (including deletion of unused strings)