Allow openid to run in stateless mode

If we pass 'storage=None' to an openid provider, it should run the
python openid consumer in stateless mode.
Adding docs for stateless openid mode and fixing logic
Merge branch 'openid' of stevearc/velruse into pull.117
support a stateless option for storage
add an extra query to populate bitbucket emails
fix openid consumer to set the provider type
update facebook to not populate some keys if they are None
update changelog
switch the default to stateless on openid providers
Merge branch 'pull.117'