Implement Token Binding.

Brings token binding to keystone server. There are a number of places
where the location or hardcoding of binding checks are not optimal
however fixing them will require having a proper authentication plugin
scheme so just assume that they will be moved when that happens.

DocImpact
Implements: blueprint authentication-tied-to-token
Change-Id: Ib34e5e0b6bd83837f6addbd45d4c5b828ce2f3bd