Install the overlay.

[smashwilson]

Use overlay decorations once they land in a release 💖

Fixes #92.

[smashwilson]

I can't do this: it would apply to all overlays, everywhere.

I'll need to send a PR to Atom adding an option to apply custom classes to each created overlay.

[smashwilson]

Er, this doesn't quite work.

Part of this is not being able to apply a width: 100% style to the overlay DOM elements, which contain the merge-conflict controls. But I'm not sure why it isn't tracking the position properly. If I understand overlays, they should position themselves directly over the decorated text.

[smashwilson]

Nope! By default, overlays are just below the marked text, for things like the autocomplete box. I'm using a negative margin to put them in the right place:

There are still a few positioning issues with certain styles. It seems like the stylesheet can cause the vertical scrollbar width to not be accurate:

[smashwilson]

Good enough for now! Much less wonky than it was.