Use cancel_record instead of removing from group

cancel_record uses Screen.remove which ensure the cursor is correctly set after
the removal.
This also ensure that cancel_record remove only the current record.

issue5852
review29641002

src/window.js

@@ -358,7 +358,7 @@
                     this.screen.current_record) {
                 result = false;
                 if ((this.screen.current_record.id < 0) || this.save_current) {
-                    this.screen.group.remove(this.screen.current_record, true);
+                    this.screen.cancel_current();
                 } else if (this.screen.current_record.has_changed()) {
                     this.screen.current_record.cancel();
                     this.screen.current_record.reload().always(function() {