Only update the topic of it has really be changed, avoid diplaying many

Only update the topic of it has really be changed, avoid diplaying many

2007-08-13 Xavier Claessens  <xclaesse@gmail.com>

	* libempathy-gtk/empathy-group-chat.c: Only update the topic of it has
	really be changed, avoid diplaying many times "Topic set to:" message.

	* libempathy-gtk/empathy-chat.c: Some Jabber chatroom sends messages
	received before we joined the room, this avoid displaying those messages
	if we already logged them last time we joined that room. Previous
	workaround prevented Empathy to log offline messages.

svn path=/trunk/; revision=255