Being able to handle arbitrary messages from other processes is a
generally useful thing to have for fine-grained control of the plugin.
Agents don't provide that, while GenServers do. I've removed all
instances of the Agent and replaced it with the GenServer and everything
appears fine so far.
Signed-off-by: Alek Ratzloff <alekratz@gmail.com>
Since route_msg expects msg.prefix to be present, every plugin that
calls route_msg when no prefix is specified in the message (e.g. with
PING messages) would cause a crash of the process.
Now, it just calls a no-op function, since all behavior covered by
route_message requires information in the prefix at some point.
Signed-off-by: Alek Ratzloff <alekratz@gmail.com>
