[devtools] don't hide warnings and errors during tests
The markdown module in jessie turns all warnings into logging calls, so
this allows me to still see deprecation warnings when running tests.
usr/bin/cubicweb-ctl usr/bin/
usr/lib/PY_VERSION/*-packages/cubicweb/cwctl.py
../cubicweb-ctl.bash_completion etc/bash_completion.d/cubicweb-ctl