Call bootstrap scripts with a tty.

The exising bootstrip-in-dir script is changing stdin to be the result
of the find command.

fix #344

contrib/bootstrap/bootstrap-in-dir

@@ -14,7 +14,10 @@ if [[ ! -d "$BOOTSTRAP_D" ]]; then
     exit 1
 fi
 
-find -L "$BOOTSTRAP_D" -type f | sort | while IFS= read -r bootstrap; do
+IFS=$'\n'
+bootstraps=( $(find -L "$BOOTSTRAP_D" -type f | sort) )
+unset IFS
+for bootstrap in "${bootstraps[@]}"; do
     if [[ -x "$bootstrap" && ! "$bootstrap" =~ "##" && ! "$bootstrap" =~ "~$" ]]; then
         if ! "$bootstrap"; then
             echo "Error: bootstrap '$bootstrap' failed" >&2