Bug 145520 Group name will not show up in group list if the group use default name and key expression has no value
Description: Group name will not show up in group list if key expression has no value. Steps to reproduce: 1. Insert a table into report, bind it to a data set 2. Switch to property editor -> groups 3. Click on add button to open new group dialog, then press ok button Expected result: A new group with default name will be added to group list Actual result: A new group is added to group list, but without group name. But when let group tab lost focus and get focus again, you can see the group name.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/Module.java
* 
	 * @return the list of exception
	 */
	public List getAllExceptions( )
	{
		return allExceptions;
	}
	/**
	 * Returns the validation executor.
	 * 
	 * @return the validation executor
	 */
	public ValidationExecutor getValidationExecutor( )
	{
		return validationExecutor;
	}
	/**
	 * Adds one validation listener. The duplicate listener will not be added.
	 * 
	 * @param listener
	 *            the validation listener to add
	 */
	public void addValidationListener( IValidationListener listener )
	{
		if ( validationListeners == null )
			validationListeners = new ArrayList( );
		if ( !validationListeners.contains( listener ) )
			validationListeners.add( listener );
	}
	/**