Renamed folders for consistency, using sim/athena/shared schema (#27)

Rename the following folders:
hal/lib/Athena -> hal/lib/athena
hal/lib/Desktop -> hal/lib/sim
hal/lib/Shared -> hal/lib/shared
wpilibc/Athena -> wpilibc/athena
wpilibc/simulation -> wpilibc/sim

Windows users may need to run gradlew clean after updating.

wpilibc/sim/include/IterativeRobot.h

@@ -0,0 +1,87 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2008-2016. All Rights Reserved.                        */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#pragma once
+
+#include "RobotBase.h"
+#include "Timer.h"
+
+/**
+ * IterativeRobot implements a specific type of Robot Program framework,
+ * extending the RobotBase class.
+ *
+ * The IterativeRobot class is intended to be subclassed by a user creating a
+ * robot program.
+ *
+ * This class is intended to implement the "old style" default code, by
+ * providing the following functions which are called by the main loop,
+ * StartCompetition(), at the appropriate times:
+ *
+ * RobotInit() -- provide for initialization at robot power-on
+ *
+ * Init() functions -- each of the following functions is called once when the
+ *                     appropriate mode is entered:
+ *  - DisabledInit()   -- called only when first disabled
+ *  - AutonomousInit() -- called each and every time autonomous is entered from
+ *                        another mode
+ *  - TeleopInit()     -- called each and every time teleop is entered from
+ *                        another mode
+ *  - TestInit()       -- called each and every time test is entered from
+ *                        another mode
+ *
+ * Periodic() functions -- each of these functions is called iteratively at the
+ *                         appropriate periodic rate (aka the "slow loop").  The
+ *                         default period of the iterative robot is synced to
+ *                         the driver station control packets, giving a periodic
+ *                         frequency of about 50Hz (50 times per second).
+ *   - DisabledPeriodic()
+ *   - AutonomousPeriodic()
+ *   - TeleopPeriodic()
+ *   - TestPeriodic()
+ *
+ */
+
+class IterativeRobot : public RobotBase {
+ public:
+  /*
+   * The default period for the periodic function calls (seconds).
+   * Setting the period to 0.0 will cause the periodic functions to follow
+   * the Driver Station packet rate of about 50Hz.
+   */
+  static const double kDefaultPeriod;
+
+  virtual void StartCompetition();
+
+  virtual void RobotInit();
+  virtual void DisabledInit();
+  virtual void AutonomousInit();
+  virtual void TeleopInit();
+  virtual void TestInit();
+
+  virtual void DisabledPeriodic();
+  virtual void AutonomousPeriodic();
+  virtual void TeleopPeriodic();
+  virtual void TestPeriodic();
+
+  void SetPeriod(double period);
+  double GetPeriod();
+  double GetLoopsPerSec();
+
+ protected:
+  virtual ~IterativeRobot() = default;
+  IterativeRobot() = default;
+
+ private:
+  bool NextPeriodReady();
+
+  bool m_disabledInitialized = false;
+  bool m_autonomousInitialized = false;
+  bool m_teleopInitialized = false;
+  bool m_testInitialized = false;
+  double m_period = kDefaultPeriod;
+  Timer m_mainLoopTimer;
+};