New Python test framework

[Greg Hudson]

On Thu, 2010-03-04 at 22:01 -0500, Ezra Peisach wrote:
> Initial testing reveals the following:
> 
> a) It would be nice if success() took an argument that could be 
> displayed to indicate what the tests were testing... fail() does - and 
> displays the message... t_general.py might mean something to you now - 
> but five years from now?

Hm, perhaps.  I was mostly trying to cut down on output clutter by
making successful tests silent, but a little bit of output wouldn't be a
terrible thing.

> b) Failure of a test does not stop the test suite

That's a mistake.  I wanted it to be like the t_whatever C programs
where the test suite would just stop when one of them failed.  I'll fix
it.