kiss: Add means of disabling find/replace in sources files

Any source starting with raw: will be used verbatim. This allows
one to disable the marker substitution for a given source.

Am open to suggestions for a different syntax to raw: though for
now it's fine.

See #242

kiss

@@ -105,6 +105,7 @@ fnr() {
     shift 1
 
     while :; do case $_fnr-$# in
+         raw:*) _fnr=${_fnr##raw:}; break ;;
         *"$1"*) _fnr=${_fnr%"$1"*}${2}${_fnr##*"$1"} ;;
            *-2) break ;;
              *) shift 2