Signals library update

From: Douglas Gregor (gregod_at_[hidden])
Date: 2001-12-24 12:05:00

I've updated the Signals library again. It is available at:
http://groups.yahoo.com/group/boost/files/Callback/signals-20011224.tgz
http://groups.yahoo.com/group/boost/files/Callback/signals-20011224.zip

Here are the changes from the last version:
    *  Update to match visit_each framework supported by Boost.Bind
    * Signals can be connected to other signals directly.
    * Signals can be connected to references to slot function objects 
(function objects are then not copied).
    * Added argI_type types to signal classes, and cleaned up the 
corresponding documentation (thanks to Bill Kempf).
    * Document noncopyable requirement (thanks to Bill Kempf).
    * "Bindable" changed to "Trackable" (thanks to Peter Dimov).
    * Added named slot connections (thanks for Peter Dimov for the 
suggestion, and Brad King for the push toward a small implementation).
    * Trackable rationale documentation (Bill Kempf).
    * Explicitly instantiate what Signals needs within the non-template 
source.
    * Tutorial extended and updated.
    * Added examples directory.
    * Added SlotFunction template parameter to specify the type of object to 
hold the slot function objects (suggested by Peter Dimov).
    * Documentation updates for signalN classes.
    * Link to all header files within the documentation for those header 
files.
    * Moved all headers except signal.hpp into signals subdirectory.
    * return_last_value renamed to last_value.
    * Proper documentation for last_value class.
    * Design documentation added.

Please use Boost.Bind and Boost.Function from CVS with the Signals library.

Tested under GCC 2.9.3, GCC 3.0.2, Comeau 4.2.45.2, and MSVC 6.0sp5. 
Borland C++ 5.5.1 currently fails to compile, and I could use some help from 
those who understand the Borland workarounds.

Comments always appreciated, and happy holidays to those celebrating.

        Doug