Implements #183 depth ray correspondences

Some improvement work to do:

• hole fill estimates
• tune parameters
• add normal checks

applications/reconstruct/src/ilw/ilw.cpp

@@ -106,7 +106,7 @@ bool ILW::process(ftl::rgbd::FrameSet &fs, cudaStream_t stream) {
 
     _phase0(fs, stream);
 
-	params_.range = 0.1f;
+	params_.range = 0.05f;
 
     for (int i=0; i<iterations_; ++i) {
         _phase1(fs, value("cost_function",3), stream);
@@ -114,7 +114,7 @@ bool ILW::process(ftl::rgbd::FrameSet &fs, cudaStream_t stream) {
             _phase2(fs, motion_rate_, stream);
         //}
 
-		params_.range *= 0.5f;
+		params_.range *= 0.9f;
 		// TODO: Break if no time left
     }