SecurityException in FileUtils.getDefaultTempDir

FileUtils.getDefaultTempDir looks for a system property giving the CXF temporary directory name. I am using CXF to call a web service from an application running under Java Web Start, which therefore doesn't have permission to access this system property and throws an AccessControlException.

The attached patch changes this so that rather than throw the exception, getDefaultTempDir treats such a permission failure the same way as if the system property were not set and generates a sensible value itself.

(observed in 2.0.3, but the method in question is the same in the svn trunk)