Fix issue of add/remove a frame at a scene before all key frames of a layer. When you added or removed a frame at a scene before all key frames of a layer, frameline was not updated correctly. It seems nothing happened, but domview is updated. This changeset fix this issue by correcting logic for boundary case.

// -*- indent-tabs-mode: t; tab-width: 8; c-basic-offset: 4; -*-
// vim: sw=4:ts=8:sts=4
var svg = require("svg");
var mbapp = require("mbapp");

app = new mbapp.app();
app.loadSVG("test.svg");
app.loop();