Add targets for the turret aiming to shoot at

This adds a basic aiming algorithm that aims at the 3-point shot when we
think it can make it, and a 2-point shot otherwise.

Note: This also formalizes the fact that we are using the origin that is
defined by sift.fbs this year.

Change-Id: I04de0d01e2596bfa75226c6ac00af1d1d08d487f
diff --git a/y2020/control_loops/superstructure/superstructure.h b/y2020/control_loops/superstructure/superstructure.h
index f66842b..cea7c6a 100644
--- a/y2020/control_loops/superstructure/superstructure.h
+++ b/y2020/control_loops/superstructure/superstructure.h
@@ -3,6 +3,7 @@
 
 #include "aos/controls/control_loop.h"
 #include "aos/events/event_loop.h"
+#include "aos/robot_state/joystick_state_generated.h"
 #include "frc971/control_loops/drivetrain/drivetrain_status_generated.h"
 #include "y2020/constants.h"
 #include "y2020/control_loops/superstructure/shooter/shooter.h"
@@ -51,6 +52,7 @@
 
   aos::Fetcher<frc971::control_loops::drivetrain::Status>
       drivetrain_status_fetcher_;
+  aos::Fetcher<aos::JoystickState> joystick_state_fetcher_;
 
   Climber climber_;
   DISALLOW_COPY_AND_ASSIGN(Superstructure);