Always sort under C locale

src/bin/sfdoc

             sfdoc__export "$format" "${RealModuleName:-$module}" "$mpath"
             ;;
         lsm)    # --lsmod
-            sfdoc__ls_m | sort
+            sfdoc__ls_m | LC_ALL=C sort
             ;;
         lsv)    # --lsvar MODULE
-            sfdoc__ls v "$mpath" | sort
+            sfdoc__ls v "$mpath" | LC_ALL=C sort
             ;;
         lsf)    # --lsfun MODULE
-            sfdoc__ls f "$mpath" | sort
+            sfdoc__ls f "$mpath" | LC_ALL=C sort
             ;;
         lsx)    # --ls [MODULE]
             case $module in
                     sfdoc__ls v "$m"
                     sfdoc__ls f "$m"
                 done \
-              | sort
+              | LC_ALL=C sort
             ;;
         man)
             which pod2man &>/dev/null \