Introduced a Duration class to ease timeout/delay configuration using natural language

git-svn-id: https://svn.forgerock.org/openig/trunk@381 dbb9e58e-28e6-4ce0-90e8-f11d9605b710
OPENIG-176 (CR-3939 && CR-4049) Implement OAuth 2.0 Resource Server support
* Introduced openig-oauth2 maven module
* AccessTokenResolver is producing an AccessToken
** OpenAm resolver is provided
* Token extraction and validation against a token info endpoint
** Expiry is verified
** Scope compatibility is verified
** In case of errors, standard RFC 6750 compliant error responses are returned
* AccessToken are cached
** Expiration delay is configurable
* Provided an EnforcerFilter that enforce a condition before delegating the execution

git-svn-id: https://svn.forgerock.org/openig/trunk@382 dbb9e58e-28e6-4ce0-90e8-f11d9605b710
Added some tests around BearerTokenExtractor
* Some cases are not covered yet, needs to re-think the header parsing to be more strict

git-svn-id: https://svn.forgerock.org/openig/trunk@383 dbb9e58e-28e6-4ce0-90e8-f11d9605b710