Spec selection without spec output

[bitprophet]

When being obsessive about test execution time, it might be nice to have an option to force spec selection (i.e. use of the nested classes, Spec class, etc) without the full tree-style output, which at least feels like it draws faster (and is certainly unarguably less screen real estate when running the test suite many times rapidly).

At the very least this would need something like --without-specplugin to disable the automatic inclusion of --with-specplugin in the spec CLI stub. (Users can technically do nosetests --with-specselector --where=tests/ to get the same effect, but I at least use the CLI stub heavily.)

Would still be very nice to preserve the "heart" of this tool and print colorized dots instead of e.g. .F...F...E...S.... in monochrome, though. Maybe just make a --compact flag or similar (maybe --compact-spec in case some other plugin somewhere wants to own --compact? Eh).