Added a single-use flag to AuthToken, and some convenience constructors for different kinds of token.

git-svn-id: https://svn.apache.org/repos/asf/wookie/trunk@1574047 13f79535-47bb-0310-9956-ffa450edef68
Replaced calls to decryptAuthToken with calls to validateAuthToken. The difference is that the validate method also checks expiry times on tokens. The call decrpytAuthToken will be made private to avoid this problem in future. Also use new convenience constructor for a standard-lifespan token

git-svn-id: https://svn.apache.org/repos/asf/wookie/trunk@1574048 13f79535-47bb-0310-9956-ffa450edef68