Code review comment for lp://qastaging/~alan-griffiths/compiz-core/refactor-Display-from-PrivateScreen

> I suggest we defer this one for a while. Especially since the last
> privatescreen tidy up caused a few regressions.
>
> At the very least, we'll need to ensure that compiz-plugins-* and
> libcompizconfig still work before approving this.

I'm conscious of problems caused by the previous tidy up and this time have contented myself with segregating code into more coherent areas.