ID 312608 - Edits to a light's xform in an upstream GafferThree, which are overridden further downstream shouldn't update LiveRender

Problem summary
When using a Hierarchical system to edit nodes further upstream, the transformation edits in the viewer should not effect the current Live Render.

For example, if your scene was setup like the following:

 Scene ----> Gaffer1 ----> Gaffer2 ---> AttributeSet ---> RenderNode

If the AttributeSet attributeEditor.exclusiveTo targets the nodes in Gaffer1, any manipulations made through the Viewer are correctly authored in Gaffer1 nodes, but the LiveRender will also update and show the result of these manipulations even if they are overriden in the downstream Gaffer2. 

Steps to reproduce

1.  Open the 'Hello Pony' example project (Toolbar -> Help -> Example projects)
2.  Create two new 'GafferThree' nodes after the GafferThree already in the file.
3.  Set the new 'GafferThree' nodes to show incoming scenes. (Top right cog in the properties)
4.  Right Click the incoming light to 'Adopt for Editing' in both nodes.
5.  Create an 'AttributeSet' node  and fill in the properties like the following picture example:

6.  Select current view & edit to 'AttributeSet1'
7.  Right click the node and set 'Live Render'
8.  In the Scene Graph, expand everything & set the 'Light' to live update. (Third checkbox)
9.  Move the light in the Viewer.

Result: The Live render should NOT update as 'GafferThree2' should be in control of the xform attributes

Reproduced by support
Katana2.6v3 - Windows 7 - CentOS6.9
Katana2.6v1 - Windows 7 - CentOS6.9
Katana2.5v7 - Windows 7 - CentOS6.9
Katana2.5v1 - Windows 7 - CentOS6.9
Katana2.1v6 - CentOS6.9

Earliest version tested
Katana2.1v6

Expected behaviour
The Live Render should not update to reflect that the edited node is not the lowest on the hierarchy list.

Actual behaviour
The Live Render updates the light, giving a false representation.