create interface IHQLCompletionHandler and make HQLCompletionHandler an implementation, use IHQLCompletionHandler in EclipseHQLCompletionRequestor
move HQLCompletionHandler to plugin org.hibernate.eclipse.console
implement and use HQLCompletionProposalProxy in org.jboss.tools.hibernate3_6
implement and use HQLCompletionProposalProxy in org.jboss.tools.hibernate4_0
implement and use HQLCompletionProposalProxy in org.jboss.tools.hibernate4_3