Move 2015-specific code to its own folder.

Known issues:
  -I didn't change the namespace for it, but I am open to discussion
   on doing that in a separate change.
  -There are a couple of files which should get split out into
   year-specific and not-year-specific files to reduce how much needs
   to get copied around each year still.
  -The control loop python code doesn't yet generate code with the
   right #include etc paths.

Change-Id: Iabf078e75107c283247f58a5ffceb4dbd6a0815f
diff --git a/frc971/zeroing/zeroing.cc b/frc971/zeroing/zeroing.cc
index d8c77e8..e54446a 100644
--- a/frc971/zeroing/zeroing.cc
+++ b/frc971/zeroing/zeroing.cc
@@ -1,6 +1,6 @@
 #include "frc971/zeroing/zeroing.h"
 
-#include <math.h>
+#include <cmath>
 #include <vector>
 
 namespace frc971 {
@@ -14,7 +14,7 @@
 }
 
 ZeroingEstimator::ZeroingEstimator(
-    const constants::Values::ZeroingConstants& constants) {
+    const constants::ZeroingConstants& constants) {
   index_diff_ = constants.index_difference;
   max_sample_count_ = constants.average_filter_size;
   known_index_pos_ = constants.measured_index_position;