Resolves #283 re-enable fxaa approx

Also adds a depth mask to only AA discontinuities

components/operators/src/antialiasing.cpp

@@ -17,6 +17,7 @@ bool FXAA::apply(ftl::rgbd::Frame &in, ftl::rgbd::Frame &out, cudaStream_t strea
 		ftl::cuda::fxaa(
 			in.getTexture<uchar4>(Channel::Colour),
 			in.getTexture<float>(Channel::Depth),
+			config()->value("threshold", 0.1f),
 			stream
 		);
 	} else {