$TESTDIR is added to the path, so this is superfluous. Also,
inconsistent use of quotes means we might have broken on tests with
paths containing spaces.
"mtn automate stdio" will break output larger than 32kB into several packets.
This ensures that we are processing all the output on the main stream and not
only the last packet.
Monotone treats branch closing ("suspending") in a similar manner to how we do
in mercurial - a cert is added to a revision that marks the branch to be hidden.
If a subsequent commit is made, the branch is effectively reopened.