Add temporary folder fall-backs to /tmp and .
Add temporary folder fall-backs to /tmp and .

If the environment doesn't have any variables telling us where the
temporary folder is, fall back to using /tmp and if that doesn't work,
try to use the current directory.

carlosmn/clar,carlosmn/clar,ethomson/clar,ethomson/clar,carlosmn/clar,vmg/clar,vmg/clar