Add handlers for channel forwarding;
If you join channel (let's say #ubuntu-release-party) which was later closed and forwared to #ubuntu, the core will still try connecting to #ubuntu-release-party; (which looks like a good behaviour) but...
It will even happend to it, if you leave #ubuntu (not #ubuntu-release-party which can't be joined) before restarting the core.
Looks like if the channel is forwared and we leave from the 'forwarded channe' the core should also mark the 'first channel, which forwared us' like a 'not connect at start';
Currently you can change the behaviour from the sqlite3;
update buffer set joined=0 where buffername="#ubuntu-release-party";