HORNETQ-1148 Bump the version to fail properly if server is older:
Connecting from a 2.3-client (now, version 123) to a 2.2 server will fail due
to serialization errors. Better a `version incompatibility` error.
Merge pull request #898 from FranciscoBorges/stop-server-sessions

First close all sessions, THEN start waiting for completion.
Merge pull request #897 from FranciscoBorges/version-hq-1148

HORNETQ-1148 Bump the version to fail properly if server is older:
Merge pull request #896 from FranciscoBorges/schema

HORNETQ-1128 Improve schema documentation, add some intra-manual links
server-stop order