revert: accept just -I/-X without paths or -a/-i (issue4592) 'hg revert -I foo' currently fails with abort: no files or directories specified (use --all to revert all files, or 'hg update 1' to update) It doesn't seem intentional that -I/-X without other paths or --all/--interactive should fail, and it doesn't seem that harmful to allow it either, so let's just do that.