[Openid-specs-mobile-profile] Issue #41: Split functionality of binding message and context (openid/mobile)

[Torsten Lodderstedt]

New issue 41: Split functionality of binding message and context
https://bitbucket.org/openid/mobile/issues/41/split-functionality-of-binding-message-and

Torsten Lodderstedt:

* provides verifiable binding between consumption and authentication device
* usually generated by the OP, mandatory to be provided by the RP in the server-initiated case (see below)
* need to have additional parameter (context) to provide RPs option to describe context and purpose of the transaction in free text