Fixed JOIN sequence

When JOINing a channel, the servers should reply with JOIN,
RPL_TOPIC and RPL_NAMREPLY  to show the client that the join was
successful, tell the client what the current topic and who is
currently in the channel.

If RPL_NAMREPLY is omitted, the user list may stay empty in
some clients
Switched order of JOIN and NICK message because clients get confused
if the JOIN message is sent with nick anonymous befor the server forced
the nick change.

Thanks @calzoneman for pointing this out.
Merge pull request #7 from Trellmor/for-cyzon/join

Fixed JOIN sequence