Bug 121498 When datasource/dataset deleted, the datasource/dataset property binding element haven't been deleted
When deleted the datasource/dataset, the datasource/dataset property binding element haven't been deleted. Expected result: This operation must be a transaction.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/Module.java
* message files for the current thread's locale. The list returned contains
	 * no duplicate keys.
	 * 
	 * @return a list of user-defined message keys.
	 */
	public List getMessageKeys( )
	{
		Set keys = new LinkedHashSet( );
		String[] transKeys = translations.getResourceKeys( );
		if ( transKeys != null )
		{
			for ( int i = 0; i < transKeys.length; i++ )
				keys.add( transKeys[i] );
		}
		
		
		String baseName = getStringProperty( this, INCLUDE_RESOURCE_PROP );
		if ( baseName == null )
			return new ArrayList( keys );
		File msgFolder = getModuleFolder( );
		if ( msgFolder == null )
			return new ArrayList( keys );
		Collection msgKeys = BundleHelper.getHelper( msgFolder, baseName )
				.getMessageKeys( ThreadResources.getLocale( ) );
		keys.addAll( msgKeys );
		return new ArrayList( keys );
	}
	/**
	 * Checks if the file with <code>fileName</code> exists. The search steps
	 * are described in {@link #findResource(String, int)}.