1. BeansWrapper/DefaultObjectWrapper instances returned by getInstance (or a special protected constructor) will now share the class introspection cache among each other. This is the most expensive structure inside BeansWrapper-s, so it has also inflated the value of caching/singletoning the object wrapper instances.

2. Revoked the generic singleton registry feature, as it was too much of code/API bloat. Instead, now it's up to the getInstance methods to deal with singletons, if it wants to. BeansWrapper and DefaultObjectWrapper now only caches the instances for the most common setting permutations. The introspection cache is now singleton anyway.
3. Some random JavaDoc and verision history fixes as I ran into them...