Added class properties jsdoc.

lib/models/email.js

@@ -14,15 +14,11 @@ var properties = {
 };
 
 /**
- * The Email Model.
+ * @property {String} to Email addressee.  Required.
- * 
+ * @property {String} from Email sender address.  Required.
- * **Properties**
+ * @property {String} subject Email subject string.  Required.
- * 
+ * @property {String} text Text body of email.  
- * - `to` - String (required)
+ * @property {String} html HTML body of email.
- * - `from` - String (required)
- * - `subject` - String (required)
- * - `text` - String
- * - `html` - String
  * 
  * @class
  * @inherits {Model}