moving JWT code to commons

git-svn-id: https://svn.forgerock.org/openam/trunk/openam@5335 0f4defcf-c51a-4c67-9f44-6fb5eba73c5d
OPENAM-2484 (CR-1730): Further improvement to remove the potential Guice dependency within the client

git-svn-id: https://svn.forgerock.org/openam/trunk/openam@5336 0f4defcf-c51a-4c67-9f44-6fb5eba73c5d