Eliminate the ClassicAdapter.

The classic EditorView no longer exists. Let's keep the adapter for now,
though, so we can handle the shadow DOM.
Force the z-index to 2.

TextEditorView.appendToLinesView locks the z-index to 1, which lets the editor
text bleed through the CoverViews. Reset it to 2 after the fact.

Kind of a dirty hack, but it'll do until I rework for the shadow DOM :wrench:
Giving Travis a kick.
Merge pull request #85 from smashwilson/overlayer

Render controls over text