[BUGFIX] upload is to be imported, pep8 changes

Change-Id: I31bd49aedf2f1d3aa7a2b94f243dc4c81a2ee7cd
Bug 58053 - py3k-ify pwb.py, check py version

 - Use builtins instead of __builtin__
 - Check for PY3 environment variable before complaining
 - check for the right py version including py3k

Change-Id: If9090c10cf00154b275053fc2aa60f33ba85181b
Merge changes If9090c10,I31bd49ae

* changes:
  Bug 58053 - py3k-ify pwb.py, check py version
  [BUGFIX] upload is to be imported, pep8 changes