Converted static accessor return values from intrusive to raw pointer.

Because there is a static intrusive_ptr holding the object anyway, there is no need for anyone else to manage references.

Also simplified the bindings by using the new return_value_policy<CastToIntrusivePtr> mechanism in a couple of additional places.
Fixed ReorderedFrameList API to use raw pointers where appropriate.
Merge pull request #314 from johnhaddon/rawPointers

Intrusive pointer -> raw pointer fixes