Correct test case data tag.
Different relative paths to test data.

For some reason, on Travis CI, the paths to testdata needs to be
prepended with "..".  This is believed to be a difference between
Windows and Linux, though it could be a difference between Qt 5.0
and Qt 5.3.

Either way, its not important - just for unit tests anyway, so lets
just support both.

This may be revisited when I start the Mac OS builds.