Force the 4 point solution to contain the lowest point

Otherwise it may be optimal to have shorter targets.  This results in
significant skew which is bad.

Change-Id: I813d7977966afacec657cd6d2b86b225dfe6e169
diff --git a/y2019/vision/target_finder.h b/y2019/vision/target_finder.h
index 0de5ad1..c7de67a 100644
--- a/y2019/vision/target_finder.h
+++ b/y2019/vision/target_finder.h
@@ -52,6 +52,10 @@
   // Given a target solve for the transformation of the template target.
   IntermediateResult ProcessTargetToResult(const Target &target, bool verbose);
 
+  // Returns true if a target is good, and false otherwise.  Picks the 4 vs 8
+  // point solution depending on which one looks right.
+  bool MaybePickAndUpdateResult(IntermediateResult *result, bool verbose);
+
   std::vector<IntermediateResult> FilterResults(
       const std::vector<IntermediateResult> &results, uint64_t print_rate,
       bool verbose);