informative msg for static scaffold=true

More informative message when static scaffold=true form is used in sacfolded Controller. 
Modification causes the expected domain class name as well as the controller name when domain class is not found.

-----------------
package vgd
class BookController {
    static scaffold=true
}
-----------------

Original msg:
| Error 2014-10-20 14:53:56,290 [localhost-startStop-1] ERROR ScaffoldingGrailsPlugin  - Cannot generate controller logic for scaffolded class true. It is not a domain class!

Proposed msg example:
| Error 2014-10-20 15:44:41,580 [localhost-startStop-1] ERROR ScaffoldingGrailsPlugin  - Cannot generate controller logic for scaffolded class Book in controller vgd.BookController. It is not a domain class!