Use -e to read

Which use readline for interactive read command (allow to do control-a/e
and such).

Change-Id: I143d6f14dd7e853197f2e30909d4f7b33262351a

stack.sh

@@ -214,7 +214,7 @@ function read_password {
         echo "It is probably best to avoid spaces and weird characters."
         echo "If you leave this blank, a random default value will be used."
         echo "Enter a password now:"
-        read $var
+        read -e $var
         pw=${!var}
         if [ ! $pw ]; then
             pw=`openssl rand -hex 10`