[Cram sanitization] path separator used to separate directory
[Cram sanitization] path separator used to separate directory

 * Allows to sanitize list of directories that can be found in environment
   variables

Signed-off-by: François Bobot <8530d62b7eab3cddb9a9239fb10975bf18a1335a@cea.fr>

dra27/jbuilder,dra27/jbuilder,dra27/jbuilder,janestreet/jbuilder,janestreet/jbuilder,janestreet/jbuilder,janestreet/jbuilder,dra27/jbuilder,dra27/jbuilder,janestreet/jbuilder,dra27/jbuilder,janestreet/jbuilder