Add optional codename to version info

src/bin/satcmd.skel

 SATURNIN_LIBEXEC_PREFIX="satcmd-"
 SATURNIN_APP_VERSION="__MKIT_PROJ_VERSION__"
 SATURNIN_APP_TAGLINE="__MKIT_PROJ_TAGLINE__"
+SATURNIN_APP_CODENAME="__MKIT_PROJ_CODENAME__"
 
 #
 # =====END BUILT PART=====

src/shellfu/saturnin.sh

     # Print version info
     #
     local tagline=${SATURNIN_APP_TAGLINE:-Some app with default tagline}
-    echo "$(basename "$0") ($tagline) $SATURNIN_APP_VERSION"
+    local maybe_codename=""
+    test -n "$SATURNIN_APP_CODENAME" && maybe_codename=" - $SATURNIN_APP_CODENAME"
+    echo "$(basename "$0") ($tagline) $SATURNIN_APP_VERSION$maybe_codename"
     return "$SHELLFU_EXIT_OK"
 }