Add support for simultaneous connections to more than one weechat

[sleep-walker]

When I try to connect to other instance of weechat, I'm asked whether the other connection should be replaced. If I refuse, no connection is made, if I agree, former connection is closed.

There should be no reason for this limitation.

[the-kenny]

Tomáš Čech [email protected] writes:

When I try to connect to other instance of weechat, I'm asked whether
the other connection should be replaced. If I refuse, no connection is
made, if I agree, former connection is closed.

Unfortunately I didn't think of multiple connections when writing
weechat.el. This results in a fairly big "singleton" that holds the data
of available channels, connection information, relevant buffers, etc.

Changing this would be quite a refactoring and I don't have plans to add
this in the foreseeable future.

I'm happy to review any Pull Requests working in this direction.