fix race and reinit conn.Me on disconnect

* due to the blocking nature of channel reads, by the time the runLoop()
  for loop exits in that goroutine, we might well be half-way through
  reconnecting to the server -- a bad time to run conn.initialise().
  move the call to initialise() into shutdown() to ensure it happens
  in a timely manner.

* On a related note, conn.Me was retaining old channel objects in it's
  Channels map. All other references to nicks and channels are erased
  in conn.initialise(), but as we keep a seperate reference to our Nick
  object in conn.Me, we need to reinit that at the same time.

irc/connection.go

@@ -69,6 +69,12 @@ func (conn *Conn) initialise() {
 	conn.Err = make(chan os.Error, 4)
 	conn.io = nil
 	conn.sock = nil
+
+	// if this is being called because we are reconnecting, conn.Me
+	// will still have all the old channels referenced -- nuke them!
+	if conn.Me != nil {
+		conn.Me = conn.NewNick(conn.Me.Nick, conn.Me.Ident, conn.Me.Name, "")
+	}
 }
 
 // Connect the IRC connection object to "host[:port]" which should be either
@@ -200,10 +206,6 @@ func (conn *Conn) runLoop() {
 	for line := range conn.in {
 			conn.dispatchEvent(line)
 	}
-	// if we fall off the end here due to shutdown,
-	// reinit everything once the runloop is done
-	// so that Connect() can be called again.
-	conn.initialise()
 }
 
 func (conn *Conn) shutdown() {
@@ -212,6 +214,9 @@ func (conn *Conn) shutdown() {
 	close(conn.Err)
 	conn.connected = false
 	conn.sock.Close()
+	// reinit datastructures ready for next connection
+	// do this here rather than after runLoop()'s for due to race
+	conn.initialise()
 }
 
 // Dumps a load of information about the current state of the connection to a