signal return values

All our signals currently return bool and make use of that fancy
combiner model provided by boost.  The return val is making it difficult
to use methods that return void.  I like the idea of having signals
return bool, but so far, wrapping void methods has been a pain and the
current syntax is ugly and non-intuitive.

So, how important is it for the signals to return bool?  Could they just
return void?  How much would that impact user and the development of
libstk apps.

Ideally, we would come up with an elegant wrapper to change the return
value of any void method (with any number of args) to true.

Darren