Fix version check warnings for httplib2 and python-gflags (used by oauth2client).

Signed-off-by: Daira Hopwood <david-sarah@jacaranda.org>
Cleanup to declare not_import_versionable and ignorable packages in _auto_deps.py

Signed-off-by: Daira Hopwood <david-sarah@jacaranda.org>
Fix pyflakes warnings.

Signed-off-by: Daira Hopwood <david-sarah@jacaranda.org>