Move JDocument to legacy tree. Not a Deprecation.

JDocument is so heavily tied to the CMS that it is difficult to use outside of the CMS in it's current state. With the massive namespace effort, I felt it would be appropriate to move JDocument to legacy, and preserve it there for downstream users. IMO, it should be transferred to the CMS altogether, but I want to provide a viable alternative before that occurs.

For or against, let it be known, or forever hold your peace. :) (only partially kidding)