Modify Server for outgoing targetting

[joel99]

Provided an array of raw user objects from #29, for each outgoing plugin, verify their .needs and provide the appropriate targetting information by reducing the user objects. Call their target functions with the targetting information.

The server should ideally behave the same way it if the outgoing plugins have no needs aka are broadcasting plugins.

This issue continues directly from #29. This is part of the #13 epic.