Introduce editor#feature event

[Piotrek Koszuliński]

Based on: ​http://ckeditor.com/forums/CKEditor/How-to-remove-attributes-which-are-removed-from-dialog-windows

It is not possible to modify feature's properties in convenient way or in some cases at all. Editor#feature should be fired when feature is registered by filter#addFeature, but before its rules/transformations/etc are registered.

This should be possible:

CKEDITOR.replace( 'editor1', {
	on: {
		feature: function( evt ) {
			if ( evt.data.name == 'table' )
				evt.data.allowedContent = 'table[border,summary];caption tbody thead tfoot;th td tr[scope]';
		}
	}
} );

[Olek Nowodziński]

I'd love to see this in upcoming releases.