cjdns-tools: init at 21.1

This adds cjdns-tools which is exposing the tools from
$cjdns/tools/ under a command named cjdns-tools
(so for ex cjdns "ping" is accessible as cjdns-tools ping <ip>)

Additionally patches cjdns tools to read admin pw from /etc/cjdns.keys

Co-authored-by: Sandro <sandro.jaeckel@gmail.com>

pkgs/tools/admin/cjdns-tools/wrapper.sh

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+
+export PATH="@@out@@/tools:$PATH"
+
+set -eo pipefail
+
+if ! cat /etc/cjdns.keys >/dev/null 2>&1; then
+  echo "ERROR: No permission to read /etc/cjdns.keys (use sudo)" >&2
+  exit 1
+fi
+
+if [[ -z $1 ]]; then
+  echo "Cjdns admin"
+
+  echo "Usage: $0 <command> <args..>"
+
+  echo
+  echo "Commands:" $(find @@out@@/tools -maxdepth 1 -type f | sed -r "s|.+/||g")
+
+  _sh=$(which sh)
+  PATH="@@out@@/tools" PS1="cjdns\$ " "$_sh"
+else
+  if [[ ! -e @@out@@/tools/$1 ]]; then
+    echo "ERROR: '$1' is not a valid tool" >&2
+    exit 2
+  else
+    "$@"
+  fi
+fi