[1.0.0] Add support to dump the current storage to LDIF.

[ChadSikorra]

This rounds out the LDIF implementation by allowing the LDAP server storage to be dumped to a LDIF via LdapServer::dump(). It streams all naming contexts to a LDIF file (including the current operational attributes). This allows it to be fed back in via LdapServer::seed.

I have two follow-ups to make with this:

• The dump process streams results to a file, which handles large directory structures easily. The seed path does not handle streaming. So for a large directory you could get into a situation where you can dump it but not seed it due to memory issues. Going to make the seed process more memory efficient in a follow up.
• The naming contexts are derived from the config on ServerOptions, which is now quite awkward since the server is basically a functional LDAP server with a storage backend. The naming contexts should be derived from what is currently in the storage backend, not the config. I will change this in a follow up.