Having self.diag and self.t.diag was confusing as one referred to TAP
output (self.diag) while the other referred to "task diagnostics"
self.t.diag.
self.diag is now gone and was replaced by self.tap with the same
behavior.
- "./run_all --fast" parallelizes all Python tests. Perl and C++ tests
are not guaranteed to run in an isolated environment, so run them
serially instead.
- Adjust some tests in order to recognize them as Python.
- Added diag.t, which simply runs the 'diagnostics' command and captures output.
The output will be gathered and stored by Flod, which means we can monitor the
platform characteristics.
