| Subject: | Add ->weaken support to postback and callbacks |
Forced reference counting in postback and callback objects makes it very
difficult to build applications where callback messages are considered
to only be advisory (and the parent is expected to shutdown at any time).
It also makes it very difficult to build large applications which have
their own heirachies of control and structure, and wish to start and
stop sessions repeatedly without the need to also continuously destroy
and recreate the same postback handles over and over again.
To deal with these situations, we should provide a mechanism to
explicitly weaken a postback or callback object.
The simplest and most back-compatible way to do this would be to allow
something like $_[SESSION]->postback('event')->weaken.