Change mix functions to only calc 'next' for the state variable being changed. Move mix functions to be last of the group.
Change mix functions to only calc 'next' for the state variable being changed.
Move mix functions to be last of the group.

cmcqueen/simplerandom,cmcqueen/simplerandom,cmcqueen/simplerandom,cmcqueen/simplerandom,cmcqueen/simplerandom