Tidy client_add
Add cf_section_dup, doesn't currently dup data, but could do in future...
Duplicate the pair's filename and line number too in cf_pair_dup
Fix cf_pair_find_next so it works correctly with a NULL pair and a NULL attr
home server free should verify pointer with talloc_get_type_abort
Automatically determine the default port based on protocol (for home_servers)
Make it possible to add home_servers without names

They function like normal home servers but can't be added to pools
Formatting
Add event_loop_started global, and remove realms initialized

It's fine for modules to add additional home servers or realms when dynamic mode isn't enabled as long as the workers haven't started processing requests
Allow coa_server in client stanzas to be a section as well as a pair

When used as a section it defines a new home_server with fields inherited from the client.  This can be used to turn all clients into CoA home servers.