Parent Switch system overhaul

[Arminando]

Currently all parent switching is hard coded into the rigs. This is alright in some cases but often a more customized solution is needed.
The idea is to create a whole new system for handling this.
How I might handle this would be to create parent "pools" that controls can be added to, and those could then be assigned to child controls as their target parents. Will need to do some prototyping to se if this idea works.