Further work on moving out legacy code; still doesn't compile.

svn path=/sandbox/boost/signals/; revision=3659
Finished moving out legacy code; compiles again; passes original tests.

svn path=/sandbox/boost/signals/; revision=3663
Minor fixes; compiles now with BOOST_SIGNALS_NO_LEGACY_SUPPORT defined.

svn path=/sandbox/boost/signal.hpp; revision=3667
Made last_value throw when it can't generate a return value, instead
of it resulting in undefined behavior.  Made last_value<optional<T> >
return uninitialized optional instead of throwing.

svn path=/sandbox/boost/last_value.hpp; revision=3671
inherit publically from runtime_error for no_slots_error.

svn path=/sandbox/boost/last_value.hpp; revision=3672
Simplified the template interface; some code cleanup; added Allocator template parameter; work-in-progress;

svn path=/sandbox/boost/signal.hpp; revision=3710
*** empty log message ***

svn path=/sandbox/boost/signals/; revision=3711
Updated tutorial to use new boost::track instead of old boost::trackable.

svn path=/sandbox/libs/signals/; revision=3722
Updated faq wrt thread-safety.

svn path=/sandbox/libs/signals/; revision=3723
Updated signalN reference to reflect changes for thread-safety.

svn path=/sandbox/libs/signals/; revision=3724
Added ThreadingModel template parameter to signal reference documentation.

svn path=/sandbox/libs/signals/; revision=3725
Made the test of an already auto-disconnected slot actually test
something (the slot was never connected to the signal).

svn path=/sandbox/libs/signals/; revision=3727
Made slots throw bad_weak_ptr when called with expired tracked
objects.  Combiners now have to catch bad_weak_ptr exceptions
thrown on slot iterator dereference.  Tracking works automatically
now for slots that call other slots.

svn path=/sandbox/boost/last_value.hpp; revision=3756
Throw more specific "expired_slot" exception, derived from bad_weak_ptr
when slot is called with an expired tracked object.

svn path=/sandbox/boost/last_value.hpp; revision=3760
tweaked no_slots_error exception.

svn path=/sandbox/boost/last_value.hpp; revision=3769
Patch from "Stjepan Rajko" <stipe@asu.edu> that fixes some
compile warnings and a compile error under MSVC.

svn path=/sandbox/boost/last_value.hpp; revision=3794
Removing files that have been copied over to 
sandbox/thread_safe_signals


svn path=/sandbox/boost/last_value.hpp; revision=6998
Fix eol-style and mime-types

svn path=/sandbox/boost/signal.hpp; revision=7564