tests/test-hgweb-removed

Fixing issue1542, adding a relevant test

inotify is smart enough to notify you about any changes in a
directory, even if you only watch the directory, and none if its
contents: the recursive add_watch I added was unnecessary.

The only thing that matters here is the recursive status update on
directory deletion.

And scan() has to be called _before_ the deferred call is registered.
(race condition: depending on the times, the previous patch could
apparently fail on the provided test. It's not the case anymore.)

echo % setting up repo
hg init test
cd test
echo a > a
hg ci -Ama
hg rm a
hg ci -mdel

echo % set up hgweb
hg serve -n test -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log
cat hg.pid >> $DAEMON_PIDS

echo % revision
"$TESTDIR/get-with-headers.py" localhost:$HGPORT '/rev/tip'

echo % diff removed file
"$TESTDIR/get-with-headers.py" localhost:$HGPORT '/diff/tip/a'