[teiid-dev] configuration.xml property definition simplifications

FYI, https://jira.jboss.org/jira/browse/TEIID-622 outlines a set of changes to remove attributes from property definitions and to replace the use of multiplicity with a an IsRequired attribute. This is considered low risk, since the changes brings the configuration in line with what is actually being used by the Designer (which doesn't use IsPreferred or multiplicity other than denoting required) and the parsing logic will still be tolerant of old definitions that use the IsHidden attribute or a required multiplicity. Steve