The core.gvfs config setting does a lot of things, including block unwanted commands.

This setting was dropped as part of the rename effort (#38) and should be put back for now.

However, there are a lot of things that config options does that we may not want it to do in the Scalar world. Update Git to split those actions apart based on other config options or add a core.scalar for our situation.

For example, we still want to block git gc, but that could be part of core.virtualizeobjects instead.