remove -std=c++0x compiler option since nobody is ready for it, and accordingly back into auto_ptr from unique_ptr

   This required the additional compiler command line option "-std=c++0x".

2) Switch to unique_ptr from auto_ptr which is C++ deprecated.

3) Change to new English layer names per mailing list discussion, see class_board.cpp.

4) When saving to *.kicad_pcb or *.kicad_mod, identify opportunities to use wildcard
   layer sets, for pads so far.

5) Switch to two std::string hashtables in pcb_parser.cpp, away from one wxString based one
   for layer names and layer sets mapping. One hashtable holds the mask, the other the index.
   Layer sets are only in the mask table.

6) Move "LOCALE_IO toggle" into PCB_IO::Format() since it is a public API function and
   caller should find it as convenient as possible to use.  LOCALE_IO should handle
   nesting OK in the case where public Format() is called from one of the Footprint*()
   functions.

7) Drop support for "export module to new library".  Creating new libraries will have to
   be handled in concert with library table entries, and we've talked recently about
   creating a better footprint library manager, one that resides in a DLL/DSO.  So
   this kind of functionality needs to be handled in there in the near future.

8) Change name of exported PCB_IO module/footprint to *.kicad_mod and not *.emp.

2) switch spec format to *.fodt, and edit it, mentioning lots of defaults.

3) Code pin_merge, but did not test it.

early work on DLL exports for sweet lib, stop using <cstdio> which mingw seems not to like cuz snprintf()

  * TokenList2DsnLexer.cmake now wraps each token enum in its own namespace. It
    also no longer setup of the "using" directive in the header file, which was
    bad behavior.  C++ enum values will have name collisions unless the enums
    themselves are different namespaces.
++new:
  * Sweet library is now a DSO/DLL.
  * Brought in SWIG to do a wrap of the Sweet DSO/DLL for unit testing
    and scripting.  The SWIG DSO/DLLs are built separate from the Sweet DSO/DLL
    and are also optional.