Java: Clean up cleanup

Use try-with-resources statements, where possible, to automatically
close FileInputStream, FileOutputStream, TJCompressor, TJDecompressor,
and TJTransformer instances.  We can't rely on the finalize() method in
the TurboJPEG classes anymore, because it has been deprecated and marked
for removal (although, as of this writing, it has yet to be removed.)

Author: dcommander