unofficial SSO support

[hartsock]

Provide pyVmomi helpers to handle WS-TRUST based authentication to a vSphere server. It should be possible to create generic SSO client code that can assist in creating and obtaining HoK tokens for use in pyVmomi proper.

We should include the first version of these as part of the tools library unofficially. That way we can refine the library feature without involving the core implementation.

[michaelrice]

Just an FYI on this subject there are 0 python libs that I could find that support WS-Trust based auth. This may be fairly painful to do with out possibly adding the support to suds (which looks like a lot of work to be honest), or just making a stand alone module that supported that auth style. Im open to suggestions here.

[hartsock]

Thanks for doing the research. If we end up having to write a WS-Trust lib for Python... I would say that's out of scope. In fact, that should probably be a whole different project for someone and we could use it here.

Have you looked at the official VMware SSO SDK? How bad do you think it would be to port that into Python?