refactor(regex): Refactor tests to be easily extensible
style(regex): Indentation
refactor(regex): Use GNUNET_CLIENT_notify_transmit_ready for Announce

This is more flexible and better suited for Announce since it does not expect
a Response.
refactor(regex): Extract parsing of AnnounceMessages to separate function
refactor(regex): Introduce a function to search for connected clients
feat(regex): Add REGEX_INTERNAL_announce_get_accepting_dht_entries
feat(regex): Add GNUNET_REGEX_announce_get_accepting_dht_entries

Closes #6
Merge pull request #7 from vsaw/6-regex-get-accept-state-dht-entries

6 regex get accept state dht entries