[WIP] Display runs in a view that comes from the bottom

Parapharsing @intothev01d, this is a rework of the UI and refactoring of the code. The script window now displays below instead of in a new pane, much like the keybinding window (toggled by `⌘-.`).

`⌘-i` toggles the script window to run or end and hide. `ctrl-c` kills the script but does not hide the view.

The title bar is set by the language or "Error" in the case of an error. All other functionality remains.

Let me know what you think but it's close to what we talked about and looks pretty native in the editor now.