[signals2][review] signals2 review results

** signals2 review results **

I am pleased to announce that the signals2 library by Frank Mori Hess
is accepted into boost, pending some conditions outlined below are
met.  I would like to thank the author for his work on this library,
and for his very responsive participation in the review.  I would also
like to thank Franz Alt, Jean-Cristophe Benoist, Vicente Botet, Fabio
Fracassi, Johan Råde, Ravikiran Rajagopal, Andrew Webber, and Jesse
Williamson for submitting reviews, and Terry Golubiewski, Michael
Marcin, and Hansjörg for additional comments regarding the library.

There were 5 votes cast for the acceptance of this library, and 3
against accepting the library at this time.  The reviewers that were
against immediate inclusion of signals2 suggested that the library
should be accepted when several stated problems are addressed
adequately.

Overall, the library was regarded as a much needed thread-safe
successor of Boost.Signals.  Those that have tried switching from
Boost.Signals to signals2 have found the switch rather painless (at
least in the cases that don't involve the Boost.Signals trackable
interface), and some reported using signals2 and/or its previous
versions in production code.  Some additional improvements that were
mentioned are an automatic connection management system based on
shared_ptr, and a change of namespace (which avoids problems with QT).

Additionally, many requests were made for improvements in the
documentation, as well as some improvements in thread-related testing
and some possible changes to the interface.  Frank has addressed many
of the issues in the review, and in many cases offered concrete steps