Re-enable waitForLoad flag on textures

[xeolabs]

In an earlier SceneJS there was an an option to suppress geometry visibility while textures load, so it looks like it would be useful to have that back.

Sascha:

You mean the waitForLoad flag? I noticed this flag and checked it out.
In v2.0 source code You have it already implemented (but just as a
property without any effects), but even without this flag the faces
should display the proper parent material/texturee values until the
own texture is loaded.