progress bar leaks during selftest

[Vincent Ladeuil]

Progress bars leaks are hard to catch while running the test suite.

I found a trick though:

  ./bzr selftest --parallel=fork --subunit >/dev/null

reveals at least one:

 / Build phase:Apply phase 2/3

I'm pretty sure I witnessed at least another one but I couldn't capture it.

[Martin Pool (mbp)]

This might be a dupe. I think they are coming from doctests, which
are not wrapped into a test ui.

It would perhaps be better to just convert those tests to unit tests.

Martin