fixed various memory leaks/overruns/etc

I found many issues using AddressSanitizer and LeakSanitizer.
diff --git a/frc971/constants.h b/frc971/constants.h
index 67c6a16..173efad 100755
--- a/frc971/constants.h
+++ b/frc971/constants.h
@@ -117,8 +117,12 @@
   double drivetrain_max_speed;
 };
 
-// Creates (once) a Values instance and returns a reference to it.
+// Creates (once) a Values instance for ::aos::network::GetTeamNumber() and
+// returns a reference to it.
 const Values &GetValues();
+
+// Creates Values instances for each team number it is called with and returns
+// them.
 const Values &GetValuesForTeam(uint16_t team_number);
 
 }  // namespace constants