bookmarks: merge suspect addchangegroup into core
This is marked with FIXME because it's not clear that it makes any sense.
Failed qimport of patches from files should cleanup by recording successfully
imported patches in series file.
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init repo
$ cd repo
$ echo a > a
$ hg ci -Am'add a'
adding a
$ cat >b.patch<<EOF
> diff --git a/a b/a
> --- a/a
> +++ b/a
> @@ -1,1 +1,2 @@
> a
> +b
> EOF
$ echo
empty series
$ hg qseries
$ echo
qimport valid patch followed by invalid patch
$ hg qimport b.patch fakepatch
adding b.patch to series file
abort: unable to read file fakepatch
[255]
$ echo
valid patches before fail added to series
$ hg qseries
b.patch