Improve the way the WYSIWYG editor can be customized from velocity

Currently, #wysiwyg_storeConfig velocity macro (from macros.vm) generates the JavaScript object that is used to configure the WYSIWYG editor. It would be great if the #wysiwyg_storeConfig macro would accept a map of configurations parameters. This way we could write:

#wysiwyg_editProperty($doc $fieldId $parameters)

being thus able to customize each editor instance.