GridLayer now managed by Level.

This is important because the thread which updates levels will soon not
be the only way that levels are built and loaded.  The editor will need
to use a different method.
Editor Flag now semi functional.

It:
 1. Loads the level
 2. Disables time clock and auto next level loading.
 3. Requires the --level flag with the --editor flag
Adding Edit and Play InfoBarLayers and RootLayers.

RootLayer has an InfoBar layer.  A RootLayer can be a PlayRootLayer or
EditRootLayer (depending on which mode we're in).  PlayRootLayer uses a
PlayInfoBarLayer and EditRootLayer uses an EditInfoBarLayer.
PlayInfoBarLayer and EditInfoBarLayer are intended to differ in
upcoming commits.