Fix --ignore-ve to allow running manage.py with no ve_mgr.

The version check could not be skipped, so you couldn't run manage.py
if it couldn't find ve_mgr in the right place to do the version check.
Now you can use --ignore-ve to do both, at your own risk.
Merge pull request #74 from aptivate/fix_ignore_ve

Fix --ignore-ve to allow running manage.py with no ve_mgr.