Bug 155509 ModuleHandle findResource method does not support .properties files
There is no fileType for .properties files in IResourceLocator
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/Module.java
}
	}
	/**
	 * Return a list of user-defined message keys. The list contained resource
	 * keys defined in the report itself and the keys defined in the referenced
	 * 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 );
		keys.addAll( BundleHelper.getHelper( this, baseName ).getMessageKeys(
				ThreadResources.getLocale( ) ) );
		return new ArrayList( keys );
	}
	/**
	 * Checks if the file with <code>fileName</code> exists. The search steps