revlog: document that mmap resources are released implicitly by GC
It's okay-ish, but currently the open fd and the mapping itself are leaked
until the indexdata is deallocated. If revlog had close(), the underlying
resources should be closed there as well, but AFAIK there's no such hook
point.
Issue351: mq: qrefresh can create extra revlog entry
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init
$ hg qinit
$ echo b > b
$ hg ci -A -m foo
adding b
$ echo cc > b
$ hg qnew -f foo.diff
$ echo b > b
$ hg qrefresh
$ hg debugindex b
rev linkrev nodeid p1 p2
0 0 1e88685f5dde 000000000000 000000000000