Premature release of $strong_self

[michaelfig]

I commented on the commit that introduced weaken $self.

With the code I attached in there, I don't see the problem of $self going to undef while commands are still pending.

Without my patch, if I have a long-running AnyEvent process that fires off commands and lets the handle go out of scope, I get undefined $self errors even though $cmd_cv has not yet been sent.

Thanks,
Michael.

[michaelfig]

#26 introduces the needed change.