Closing inactive connections OR user connections limits

I have read on the archives some type of per user limit that will be
available in 7.3, but what do I do in the meantime with a 7.2.X.

Basically I came this morning to find a developer had a bug in a program
and used up all the connections. Could I have safely killed those
connections?

I had to do a "pgsql stop -m fast" to free the connections, but I had some
pending operations which now I will have to redo, not to mention the
vacuum full failed last night because of the open connections.

In all the archives I read there seems to be a negative view on timeouts.
I think that after 4 hours of no activity, at least in my case, I
definitely want those connections dead.

In particular this is a reporting server and I delete/reload millions of
records daily so anything which stops the vacuum full at night is a big
problem for me.