* ie. not just an unnormalised mantissa plus biased exponent, it has proper
IEEE style float properties with hidden bit on the mantissa etc. So full
decoding is necessary, contrary to what some of the docs say :(.
* http://blog.selfshadow.com/2012/11/12/counting-quads/
* Quad Overdraw based on ScenePS4 from the revised implementation. The
colours are new, up to 20 levels. Picking pixels shows the overdraw level
* Available per-pass and per-drawcall, a pass defined the same way as in
the mesh view, drawcalls since last clear or RT change.
* List of events now passed through to RenderOverlay the same as RenderMesh
Dzmitry Malyshau