Revert pre-pending behavior of saturnin__conf_mkpath()

Turns out this was not a good idea as it would too easy to trigger.
If a saturnin sub-command was called from within itself (or another other
sub-command), the $SATURNIN_CONF_PATH computed earlier would just double,
leading to unwanted behavior of saturnin__conf_find(), which would find
items twice.

The original problem should be adressed another way; the testing case
be covered by either writing tests on a lower level; eg. unit tests
and use saturnin__conf_find() or saturnin__conf() without forking.

Another solution on part of Saturnin could be to introduce different
variable (e.g. SATURNIN_CONF_DIRS) for values computed by launcher
and keep $SATURNIN_CONF_PATH just for user.

src/saturnin.sh.skel

 
 saturnin__conf_mkpath() {
     #
-    # Print new $SATURNIN_CONF_PATH by appending locations $@
+    # Compose new value for $SATURNIN_CONF_PATH from locations $@
     #
     # Usage:
     #
     #     saturnin__conf_mkpath DIR [DIR..]
     #
-    # First repeat elements of $SATURNIN_CONF_PATH unless it's empty.
-    # Then go through each DIR and print it, unless it ends with "/ini.d",
+    # Go through each DIR and print it, unless it ends with "/ini.d",
     # in which case list its subdirectories, sorted by C locale (this allows
     # for modular configuration).
     #
     #
     local location      # one location argument
     local path          # one path listed
-    test -n "$SATURNIN_CONF_PATH" && echo -n "$SATURNIN_CONF_PATH:"
     for location in "$@";
     do
         test -d "$location" || continue