For each test x, there are several files:

x.conf - the configuration file containing the formatting options
x.xml - the input XML document
x.res - the expected result from xmlformat

To run the test, type "./runtest x" in the parent directory.
This will generate output into the file x.out, compare it to
x.res, and display a diff if they are different.  To run all
the tests, type "./runtest all".

runtest uses xmlformat.pl by default.  To use xmlformat.rb,
use runtest -r.