Merge branch 'tm/fetch-prune'

Fetching 'frotz' branch with "git fetch", while having 'frotz/nitfol' remote-tracking branch from an earlier fetch, would error out, primarily because the command has not been told to remove anything on our side. In such a case, "git fetch --prune" can be used to remove 'frotz/nitfol' to make room to fetch and store 'frotz' remote-tracking branch. * tm/fetch-prune: fetch --prune: Run prune before fetching fetch --prune: always print header url