Simplifying UniformMap updating

Simplifying UniformMap updating

Removed scene-graph ConnectionChangePropagator - now only need to know
if shader is attached to renderer, and that is already done through a
different mechanism.

Changed CollectedUniformMap into it's own struct. Now has a change
counter that increments any time the map is altered.

Instead of having lots of flags indicating if uniform maps have
changed, UniformMap now updates it's change counter whenever a
property is registered with the PropertyOwner (e.g. Node, Renderer or
Shader).

During Update, SceneGraph::Renderer collects the uniform maps into one
only if the renderer is added to a RenderList, i.e. if it's going to
be rendered. At this point, the change counter is updated.
Nothing is done if the renderer is not visible.

During Render, the Render::Renderer checks if the node uniform map
change counter or the renderer data provider's uniform map change
counter are different, if so, then it knows it needs to update the
uniform locations for newly registered properties.

Change-Id: I0ff861a7e97736dae059d94f54618195d0471343