Remove gc_upload.py

We use GitHub now rather than Google Code
and Google Code is deprecating supporting file uploads anyway.
print_freetds_version.py => print_versions.py

The latter is more general, as it prints out:

  - _mssql.__version__
  - pymssql.__version__
  - pymssql.get_dbversion()
Get PYMSSQL_VERSION from pymssql_version

instead of duplicating and having inconsistency