* add xnode.cpp and xnode.h which can be used to output either an XML or
    S-expression document file.
  * Add class STREAM_OUTPUTFORMATTER which is a richio class which can write
    to any of the wxOutputStream derivatives, such as file, socket, zip, tar.
  * Added netlist.keywords
++eeschema
  * netform.cpp can now output S-expression OK, although I have it commented out
    pending the addition of a UI for it.

  * Found several speed optimizations in the netlist export code.
  * Fixed a bug in EXPORT_HELP::FindAllInstancesOfComponent() that I had broke.
  * Now sort the pins properly if they have pin numbers like A1 and A10,
    i.e. alphanumerics in them.

netlist export speed optimizations, bug fix in NETLIST_HELP::FindAllInstancesOfComponent that I put in there yesterday.

Improve code performance and appearance

Updated boost::polygon from http://svn.boost.org/svn/boost/trunk/boost/polygon (boost 1.44) Seems fix some issues.

Updated boost::polygon from http://svn.boost.org/svn/boost/trunk/boost/polygon (boost 1.44) Seems fix some issues.

  * Now link with XML support within wxWidgets.
  * Start of export the generic netlist in XML.  Still need to rework the chain
    loaded netlist plugin.
  * OBJ_CMP_TO_LIST class now uses a std::string to hold the 8 bit string m_Ref,
    but hides this behind accessors which provide for both Unicode and 8 bit
    set and get functions.
  * build_BOM.cpp retains the selected filename on subsequent runs as a default.
  * Code cleaning, especially in build_BOM.cpp.

added " pcbnew module editor toolbar items now in menubar" patch from Jerry Jacobs. Fixed TODO, and some issues.
Fixed some minor translation issues (different help texts for the same command in tools and menus).
minor code cleaning.
fixed minor warnings in debug mode.

minor code cleaning. fixed minor warnings in debug mode.

Fixed some issues with wxWidgets 2.9.1 (fixed Gerbview and Pcbnew crashes under Linux when starting. Could explain also crashes under MACOSX)
Code cleaning.
pcbnew:
    Added experimental zone fill calculations with boost::polygon
    old file zones_convert_brd_items_to_polygons.cpp has now 2 versions:
    zones_convert_brd_items_to_polygons_with_Boost.cpp use boost::polygon to calculate filled areas
    zones_convert_brd_items_to_polygons_with_BKbool.cpp use kbool (code cleaned).
    >>> to use boost polygon version:
        call cmake with option: -DUSE_BOOST_POLYGON_LIBRARY=ON
Eeschema: added patches from Yuri Khalyavin

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