Use trap to remove TMPDIR in tests

This removes the generate temporary directories used by the test code
even when there's an unexpected failure, which is common now that
they're all "set -ex".
Test "pconfigure --version"

The only test here is that running

$ pconfigure --version

doesn't generate a Makefile, as opposed to actually trying to parse
any of the output format.
Bump version to 0.4.0