Build: Fix 'tjtest' target on Windows

Build: Fix 'tjtest' target on Windows

tjbenchtest and its Java derivatives are useful for rooting out hidden
problems with the more esoteric TJBench and TurboJPEG features.  For
instance, on Windows, running tjbenchtest uncovered
5fce2e942136cb70e5a30ff15a2d58b07947aa84.

This commit also causes tjbenchtest and tjbenchtest.java to append -yuv
and -alloc to their log file names, depending on the arguments passed,
and it causes the build system to clean up those log files when the
'testclean' target is built.