added python_cfg_example for Frank

This is an example of using CMSSW's python configuration utilities stand alone in PAC.

The key is to link against the CMSSW libs properly.  See externals/build/cmssw/jamfile.jam and analysis/python_cfg_example/jamfile.jam.

Note: the externals/build/cmssw/jamfile.jam can in principle be used to link against any lib from CMSSW as long as the names of the module/package that you with to link against has been added to this jamfile.