Move username & password to app->params()

thanks for the restfull extension, works like a charm. 

i have moved hardcoded username & password from the extension to the app params, so the controller doesn't need to be edited and all the params are at a central place.

	'params'=>array(
		'RESTusername' => 'admin@restuser',
		'RESTpassword' => 'admin@Access',
	),

greets
 KoS