Make the fast thresholding work

The only functional change was removing the block which did the same
algorithm non-flattened. It has tests now to verify it does the same
thing as the slow version.

Change-Id: I63da1a6374c2adfabf764b62d5c33f91897ce2a7
diff --git a/aos/vision/blob/BUILD b/aos/vision/blob/BUILD
index 2e77079..81afb93 100644
--- a/aos/vision/blob/BUILD
+++ b/aos/vision/blob/BUILD
@@ -45,6 +45,7 @@
     ],
     deps = [
         ":range_image",
+        "//aos/logging",
         "//aos/vision/image:image_types",
     ],
 )