Added class WebGLProperties, webgl properties now stored in that class. Checks for uuids and existance of properties encapsulated in this class

webgl props are removed in one go in object deallocation, added better example, removed other examples, added check for properties at entrance of each function that uses properties

decoupled webgl properties and buffers from renderable objects and attributes. Scenes and objects no longer coupled to renderers and may be used between multiple renderers.

Improve pipelining: submit buffer updates in order that they will be
rendered before they are rendered to allow for them to complete before
the data is required.

TO DO: *NeedsUpdate, CustomAttributes, Skinning, MorphTargets.

This allows rendering the same geometry with different WebGLRenderers.