- Put more information in the token mail (registry), such as:

  - the ip address of the network being built
  - the creator of the network ( add option in registry ? )

- Babel limitations:

  - Babel must be able to set source address on routes it installed. Otherwise,
    a wrong IP will be selected if managed interfaces already have several
    public IPv6. If there's only one interface like this, a workaround is to
    use --main-interface option on it.

- Filter non-routable IPs. Add an option not to do it.

- Abort in case of import child process failure (babel, openvpn server,
  openvpn client if run with --client).

- registry: add '--home PATH' command line option so that / display an HTML
  page from PATH (use new str.format for templating)

- Better UI to revoke certificates, for example with a HTML form.
  Currently, one have to forge the URL manually. Examples:
    wget -O /dev/null http://re6st.example.com/revoke?cn_or_serial=123
    wget -O /dev/null http://re6st.example.com/revoke?cn_or_serial=4/16
