When running tests in parallel, test runner does not display colors

[brson]

The control characters seem to cause strange artifacts so colors are disabled.

[brson]

I don't think 828d067 is correct, for reasons I left on the commit.

[brson]

We could just hunt down all the tests that log to error or print to stdout and make them log to debug instead, then call it a day. Seeing the pretty colors is super nice. Probably 828d067 should still be reverted though, unless there's something about it I'm missing.

[lht]

Sorry. I'll revert the commits.

[catamorphism]

Added far-future milestone

[catamorphism]

Bug triage. Far-future still seems right.

[metajack]

Triage bump. There's been no change.

[treeman]

Triage bump. Still relevant.

[brson]

I believe the test runner captures stdio now. It should be safe to print colors carefully.