SI-6289 Paulptest demonstrating javac errors

This is Paul's test demonstrating that Javac errors are
correctly transcribed in the test transcript.

A gratuitous Scala class is added to a later round to
show that the test halts after the first error.

The runner must supply absolute paths to javac so that
absolute paths are reported in errors and stripped away
by partest.

The check file is corrected for Java 6.

A feature for flexible check diffing must wait.