annotation: added region support to annoations

pkg/services/sqlstore/annotation.go

@@ -23,6 +23,17 @@ func (r *SqlAnnotationRepo) Save(item *annotations.Item) error {
 	})
 }
 
+func (r *SqlAnnotationRepo) Update(item *annotations.Item) error {
+	return inTransaction(func(sess *xorm.Session) error {
+
+		if _, err := sess.Table("annotation").Id(item.Id).Update(item); err != nil {
+			return err
+		}
+
+		return nil
+	})
+}
+
 func (r *SqlAnnotationRepo) Find(query *annotations.ItemQuery) ([]*annotations.Item, error) {
 	var sql bytes.Buffer
 	params := make([]interface{}, 0)