allow for anonymous access to APIs with authentication

[ahmadnassri]

an "anonymous" consumer can be used to refer to none-authenticated caller to the API, perhaps an internal reference or an operator created one with a flag anonymous: true

should also allow for setting plugin rules as regular consumers, used when authentication plugins are present and no Authentication headers are sent.

[thibaultcha]

Not sure if this has anything to do with #475

[ahmadnassri]

thanks couldn't find that one! closing in favor of this one as its better described here.

[Tieske]

merged and available in the 0.10 RC. closing this