Use custom name for tempdir

src/ffoo/saturnin_www.sh

     # Apply this filter to args or clipboard, and either use head -1 or
     # if you are brave, open all URIs.
     #
-    local d=$(mktemp -d)
+    local d=$(mktemp -d -t saturnin_www.XXXXXXXX)
     pushd $d >&/dev/null
         ##
         # heat up and fill pipes