Removed unused file
Rewriter now performs proper imports
Further changes to make u2py into a proper package

+ Data files moved to their module folders. Changes to reflect this were made to setup.py,
  setup_py2exe.py, MANIFEST.in and module config files.
+ u2.py and process_reader.py now use config.py from the start folder only when it's present.
  Otherwise, default config.py from appropriate modules will be used.