IECoreScene : Remove CurveExtrudeOp

I don't see how this can be useful any more, since none of our renderer backends support PatchMeshes. We're also moving away from Ops in favour of Algo.

Author: johnhaddon

Changes

@@ -15,6 +15,7 @@ Breaking Changes
 - Renderable : Removed `render()` method.
 - CoordinateSystem : Removed transform.
 - Options : Removed.
+- CurveExtrudeOp : Removed.
 - Renderer, AttributeBlock, EditBlock, MotionBlock, TransformBlock, WorldBlock : Removed.
 - IECoreHoudini : Removed.
 - IECoreMaya : Removed.

include/IECoreScene/CurveExtrudeOp.h

@@ -98,7 +98,7 @@ enum TypeId
 	MeshTangentsOpTypeId = 108055,
 	PatchMeshPrimitiveTypeId = 108056,
 	CurvesPrimitiveParameterTypeId = 108057,
-	CurveExtrudeOpTypeId = 108058,
+	CurveExtrudeOpTypeId = 108058, // Obsolete, available for reuse
 	ParameterisedProceduralTypeId = 108059,
 	NParticleReaderTypeId = 108060,
 	CurvesMergeOpTypeId = 108061,