change serverID (used for iss and aud fields) to a URI
ID-180 store verificationToken as a JWS inside a JWE &
- rename class JWT --> JWS
- catch parseJWS exceptions in the method itself
- move token data validators to a new class (Tokens.scala)
- split completeAttributeVerify in 2 because of length
- verify iss and aud to match serverID in subjectToken and verificationToken