Remove scene object null check on SceneGraph.AddSceneObject().  Complain explicitly if there's an attempt to add any object with a zero UUID.
Remove scene object null check on SceneGraph.AddSceneObject().  Complain explicitly if there's an attempt to add any object with a zero UUID.

Callers themselves need to check that they're not attempting to add a null scene object.

QuillLittlefeather/opensim-1,M-O-S-E-S/opensim,Michelle-Argus/ArribasimExtract,bravelittlescientist/opensim-performance,M-O-S-E-S/opensim,Michelle-Argus/ArribasimExtract,OpenSimian/opensimulator,bravelittlescientist/opensim-performance,justinccdev/opensim,ft-/arribasim-dev-tests,ft-/opensim-optimizations-wip-extras,ft-/opensim-optimizations-wip,Michelle-Argus/ArribasimExtract,BogusCurry/arribasim-dev,TomDataworks/opensim,QuillLittlefeather/opensim-1,ft-/opensim-optimizations-wip-tests,ft-/arribasim-dev-tests,EriHoss/OpenSim_0.8.2.0_Dev_LibLSLCC,rryk/omp-server,OpenSimian/opensimulator,Michelle-Argus/ArribasimExtract,ft-/opensim-optimizations-wip-tests,ft-/arribasim-dev-extras,TomDataworks/opensim,ft-/opensim-optimizations-wip,RavenB/opensim,ft-/opensim-optimizations-wip-extras,ft-/arribasim-dev-extras,bravelittlescientist/opensim-performance,ft-/arribasim-dev-extras,justinccdev/opensim,rryk/omp-server,ft-/opensim-optimizations-wip-tests,M-O-S-E-S/opensim,EriHoss/OpenSim_0.8.2.0_Dev_LibLSLCC,EriHoss/OpenSim_0.8.2.0_Dev_LibLSLCC,EriHoss/OpenSim_0.8.2.0_Dev_LibLSLCC,ft-/opensim-optimizations-wip,M-O-S-E-S/opensim,QuillLittlefeather/opensim-1,bravelittlescientist/opensim-performance,ft-/arribasim-dev-extras,rryk/omp-server,OpenSimian/opensimulator,justinccdev/opensim,ft-/opensim-optimizations-wip-extras,ft-/opensim-optimizations-wip-tests,ft-/arribasim-dev-extras,TomDataworks/opensim,ft-/arribasim-dev-extras,EriHoss/OpenSim_0.8.2.0_Dev_LibLSLCC,BogusCurry/arribasim-dev,RavenB/opensim,Michelle-Argus/ArribasimExtract,RavenB/opensim,RavenB/opensim,RavenB/opensim,M-O-S-E-S/opensim,Michelle-Argus/ArribasimExtract,OpenSimian/opensimulator,bravelittlescientist/opensim-performance,QuillLittlefeather/opensim-1,ft-/arribasim-dev-tests,rryk/omp-server,justinccdev/opensim,TomDataworks/opensim,EriHoss/OpenSim_0.8.2.0_Dev_LibLSLCC,QuillLittlefeather/opensim-1,TomDataworks/opensim,TomDataworks/opensim,OpenSimian/opensimulator,ft-/opensim-optimizations-wip-extras,ft-/opensim-optimizations-wip,BogusCurry/arribasim-dev,justinccdev/opensim,rryk/omp-server,QuillLittlefeather/opensim-1,ft-/opensim-optimizations-wip-extras,OpenSimian/opensimulator,ft-/arribasim-dev-tests,QuillLittlefeather/opensim-1,OpenSimian/opensimulator,EriHoss/OpenSim_0.8.2.0_Dev_LibLSLCC,M-O-S-E-S/opensim,ft-/opensim-optimizations-wip-tests,justinccdev/opensim,rryk/omp-server,ft-/arribasim-dev-tests,RavenB/opensim,BogusCurry/arribasim-dev,bravelittlescientist/opensim-performance,BogusCurry/arribasim-dev,M-O-S-E-S/opensim,ft-/arribasim-dev-tests,TomDataworks/opensim,RavenB/opensim,BogusCurry/arribasim-dev