Test timeout policy should be decided by runner

[jml]

At the moment, any test made from t.trial.unittest.TestCase will have a two minute default timeout. This is incorrect. The default timeout for tests should be specified by the runner, not by the Trial API. By default, tests should not timeout.

[glyph]

I'm not sure I agree with:

"By default, tests should not timeout."

but then I'm not sure what you're referring to. I think I agree with the general sentiment here of who should decide and why, but the default configuration of the default runner should specify a reasonable timeout.

[exarkun]

Like glyph, most of this ticket makes sense to me, but the last sentence of the description also confuses me. This test suite:

from twisted.trial.unittest import TestCase
from twisted.internet.defer import Deferred
class HangingTests(TestCase):
    def test_hangs(self):
        return Deferred()

should not result in trial test_hangs requiring a ^C (or other signal) to cause it to complete.

[jml]

Right. The default configuration of the default runner should timeout tests.

What I meant was that, HangingTests('test_hangs').run(TestResult()) should hang unless an explicit timeout-ing API is called.

[exarkun]

It would also be very useful if the timeout could be specified as a command line argument to the trial program.

I kind of want this for a number of reasons, so I'm bumping the priority.