Use wxXmlNode::GetProperties() and not GetAttributes() since the former is more widely available in older wxXml libs

* Fixed multiple line strings causing MSVC compile errors.
* Fixed memory leak when attempting to add duplicate library component.
* Added recent cmake generated files to bazaar ignore list.
* Minor code cleaning.

    Revise TokenList2DsnLexer.cmake to take outCppFile and outHeaderFile optinally
    and enum mandatorily.  Standardize the script's invocation technique within
    all the CMakeLists.txt files.

    Revise TokenList2DsnLexer.cmake to take outCppFile and outHeaderFile optinally
    and enum mandatorily.  Standardize the script's invocation technique within
    all the CMakeLists.txt files.

    Revise TokenList2DsnLexer.cmake to make an entire derived lexer class that
    returns the proper enum type for superior debugging.
++eeschema
  * netform.cpp now outputs the allowed footprint filters for a given library
    component.
  * There is an auto-generated class called NETLIST_LEXER which is defined in
    from netlist.keywords by TokenList2DsnLexer.cmake into netlist_lexer.h, that
    may be the basis of loading a S-expression form of the generic netlist format
    which is written from netform.cpp.

  * 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.