[AbstractComponent] - Enforcing that _computeLayout must be called before _render

Trying to enforce that _render should only be called if space is allocated to the component.  This is to prevent times when the space is not allocated yet by methods like _computeLayout but things will try to render anyways (due to scale broadcasting or similar). 

For @tkimcoop , a regression test should be enough, and a before-after on what happens on high-costing animations would be nice.

Fixes #867