[BEANUTILS-455] WrapDynaBean now allows passing its class to the constructor.

This makes it possible to construct the class externally (using custom
configuration) and then pass the fully initialized class object to the bean
instance.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/beanutils/trunk@1547901 13f79535-47bb-0310-9956-ffa450edef68