This pipeline runs the XProc test suite and reports the results.
It has three options: host, username, and
password.
The host option is used to specify the host to use
in the URIs of test suite documents. (Because Norm has a local copy of
http://tests.xproc.org/.)
The username and password are used to submit
the test results to http://tests.xproc.org.
If run without a password, it simply outputs the report document.