* IMP::Object now defines pure virtual methods IMP::Object::get_version_info() and IMP::Object::show(). All non-abstract classes which inherit from IMP::Object must implement them. Doing this means they are more uniformly implemented and are documented in one place.

* IMP::Object is now reference counted (the only objects this changes are IMP::Model and IMP::Optimizer). As a result optimizers and IMP::Model objects must be created on the heap.

* IMP::RefCounted has had its name changed and no longer inherits from IMP::Object. This makes it easier to use independently.

* the docs for reference counting (IMP::RefCounted) and Decorators decorators (and IMP::Decorator) have been improved

* running doxygen produces no warnings. Let's try to keep it that way. Run scons doc > /dev/null before you check in large blocks of new code to make sure that you didn't introduce warnings.

* Helper classes have been added to make SingletonModiefier and PairModifier objects look like functors for C++ and python. This makes it so you can use map in Python and for_each in C++. See IMP::SingletonFunctor and IMP::PairFunctor for more information.

* The recent changes page has moved to a doxygen page to make it easier to link changes back to the relevant source code. This hasn't yet made it to the web as I keep breaking the build. Hopefully tonight :-)