Need more information than just the mech OID in the exception message for BAD_MECH

When users calls JGSS APIs w/ unsupported mechanisms, for example: when trying to create a credential, the thrown exception only dispalyed the Oid. It should include more information to help users troubleshooting.

Here is a sample stack trace:
GSSException: 1.3.6.1.5.5.2
       at sun.security.jgss.ProviderList.getMechFactory(ProviderList.java:187)
       at sun.security.jgss.ProviderList.getMechFactory(ProviderList.java:154)
       at sun.security.jgss.GSSManagerImpl.getNameElement(GSSManagerImpl.java:187)
       at sun.security.jgss.GSSNameImpl.getElement(GSSNameImpl.java:437)
       at sun.security.jgss.GSSCredentialImpl.add(GSSCredentialImpl.java:380)
       at sun.security.jgss.GSSCredentialImpl.<init>(GSSCredentialImpl.java:58)
       at sun.security.jgss.GSSManagerImpl.createCredential(GSSManagerImpl.java:145)
       at TestNativeSpi.testCred(TestNativeSpi.java:147)
       at TestNativeSpi.main(TestNativeSpi.java:318)