Added an API for requesting a new token, either on first render to exchange a single-use token for a session token, or periodically to avoid token expiry.

git-svn-id: https://svn.apache.org/repos/asf/wookie/trunk@1574091 13f79535-47bb-0310-9956-ffa450edef68
Added token controller to the API

git-svn-id: https://svn.apache.org/repos/asf/wookie/trunk@1574092 13f79535-47bb-0310-9956-ffa450edef68