confd: add script path option (-s) to migrate script

This allows a user to run in on any system which has the Infix source
code that contains the modification scripts.

Signed-off-by: Richard Alpe <richard@bit42.se>

src/confd/bin/migrate

@@ -13,6 +13,7 @@ usage()
     echo "  -h       This help text"
     echo "  -i       Edit file in-place instead of sending to stdout, like sed"
     echo "  -q       Quiet, skip normal log messages, only errors are logged"
+    echo "  -s PATH  Specify custom script path"
     echo
     echo "By default, this script reads a .cfg file on stdin, or as the first"
     echo "non-option argument, then migrates it to a new syntax on stdout."
@@ -121,7 +122,7 @@ chmod 600 "$tmp"
 
 trap cleanup INT HUP TERM EXIT
 
-OPTS=$(getopt -o b:chiq -- "$@")
+OPTS=$(getopt -o b:chiqs: -- "$@")
 eval set -- "$OPTS"
 
 while [ -n "$1" ]; do
@@ -143,6 +144,10 @@ while [ -n "$1" ]; do
         -q)
             quiet=1
             ;;
+        -s)
+            scripts=$2
+            shift
+            ;;
         --)
             shift
             break