Revert "Merge branch 'jg/status-config'"

This reverts commit 1a22bd31f0a5130ce6c934951a5526ceb774c2be, reversing
changes made to 3e7a5b489e45ae8a3a0b222893d58b172d883136.

It makes it impossible to "git commit" when status.short is set, and
also "git status --porcelain" output is affected by status.branch.