build of pyexpat and elementtree modules
- add patch adapted from upstream (patch 7) to add support for building
against system expat; add --with-system-expat to "configure" invocation
- remove embedded copies of expat and zlib from source tree during "prep"
- explicitly list all lib-dynload files, rather than dynamically gathering
the payload into a temporary text file, so that we can be sure what we
are shipping
- introduce a macros.pybytecompile source file, to help with packaging
python3 modules (Source3; written by Toshio)
- rename "2to3-3" to "python3-2to3" to better reflect python 3 module
packaging plans
curses configuration in Modules/Setup.dist, so that the curses modules
are built using setup.py with the downstream default (linking against
libncursesw.so, rather than libncurses.so), rather than within the
Makefile; add a test to %%install to verify the dso files that the
curses module is linked against the correct DSO (bug 539917; changes
_cursesmodule.so -> _curses.so)
