Added custom validation support to validator

lib/utils/validation.js

@@ -115,5 +115,19 @@ var validateType = (require.modules || {}).validation = module.exports = functio
 	if (schemaType === Boolean) return assert(_.isBoolean(value), 'boolean');
 	if (schemaType === Date) return assert(_.isDate(value), 'date');
 	if (schemaType instanceof RegExp) return assert(schemaType.test(value || ''), 'regex match on ' + schemaType.toString(), (value || 'nothing').toString());
+
+	var virtualThis = {
+		fail: fail,
+		assert: assert,
+		pass: pass
+	};
+
+	for(var i = 0; i < validateType.extra.length; i++) {
+		var result = validateType.extra[i].call(virtualThis, schemaType, value, property);
+		if(result) return result;
+	}
+
 	return assert(value instanceof schemaType, 'instanceof ' + schemaType.toString());
-};
+};
+
+validateType.extra = [];