Uniquify tjbenchtest log file names based on args

+ clean up log files when 'make testclean' is invoked
+ fix 'tjbenchtest -yuv -alloc'
+ fix tjexampletest so that it creates images under /tmp
+ clean up tjexampletest

tjbenchtest.java.in

@@ -33,8 +33,6 @@ if [ -d $OUTDIR ]; then
 fi
 mkdir -p $OUTDIR
 
-exec >$EXEDIR/tjbenchtest-java.log
-
 if [ $# -gt 0 ]; then
 	if [ "$1" = "-yuv" ]; then
 		NSARG=-nosmooth
@@ -60,6 +58,8 @@ if [ $# -gt 0 ]; then
 	fi
 fi
 
+exec >$EXEDIR/tjbenchtest-java$YUVARG.log
+
 # Standard tests
 for image in $IMAGES; do