Implements #133 point alignment

Further work to be done:

• switch to depth ray cast correspondences
• use normals etc in correspondences

components/renderers/cpp/src/splatter.cu

@@ -104,7 +104,7 @@ __global__ void dibr_attribute_contrib_kernel(
     //if (abs(d - camPos.z) > DEPTH_THRESHOLD) return;
 
 	const float4 colour = (params.m_flags & ftl::render::kShowDisconMask && worldPos.w < 0.0f) ?
-			make_float4(0.0f,0.0f,255.0f,255.0f) :
+			make_float4(0.0f,0.0f,255.0f,255.0f) :  // Show discontinuity mask in red
 			make_float4(colour_in.tex2D(x, y));
     //const float4 normal = tex2D<float4>(camera.normal, x, y);