Partial revert of 9fb51aecd8e4debd4421791a37e091afc708a8ed

* The AuthenticationType CLEARTEXT was not a fully different option but a
  simple name change for USERPASSWORD and was never included in a final
  release.

* Reverts both AuthenticationType and Handshake to reflect 8.7 teiid client
Merge pull request #391 from phantomjinx/master

Partial revert of 9fb51aecd8e4debd4421791a37e091afc708a8ed