Resolve the working directory in a different manner.

All of a sudden some test cases started failing. The work directory
as reported by the system property "work.dir" suddenly uses different
casing.

Either this is due to a newer version of IntelliJ IDEA (14, although
I can't fathom way), or it's something else. No idea.

Anyway, performing "toRealPath" on the resolved working directory
fixes it.