Xfiles/Util/cmakeUtil/test_ndiff.sh must be rewritten to be portable. The way to find the tool 'ndiff' is durty and hard coded for titan. It should not work on other platform as it is. The 'find 'command must be improved and a warning message should be written if 'ndiff' is not found. This bug may indicate that some ndiff_test passed while the test is not done in fact.