subrepo: refuse to commit subrepos if .hgsub is excluded (
issue2232)
% prepare repo
adding a
% import patch
applying patch from stdin
patching file a
Hunk #1 succeeded at 43 (offset 34 lines).
Hunk #2 succeeded at 87 (offset 34 lines).
Hunk #3 succeeded at 109 (offset 34 lines).
a
% compare imported changes against reference file