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/athena/include/AnalogAccelerometer.h

@@ -0,0 +1,52 @@
+/*----------------------------------------------------------------------------*/
+/* 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 "AnalogInput.h"
+#include "LiveWindow/LiveWindowSendable.h"
+#include "PIDSource.h"
+#include "SensorBase.h"
+
+#include <memory>
+
+/**
+ * Handle operation of an analog accelerometer.
+ * The accelerometer reads acceleration directly through the sensor. Many
+ * sensors have multiple axis and can be treated as multiple devices. Each is
+ * calibrated by finding the center value over a period of time.
+ */
+class AnalogAccelerometer : public SensorBase,
+                            public PIDSource,
+                            public LiveWindowSendable {
+ public:
+  explicit AnalogAccelerometer(int32_t channel);
+  explicit AnalogAccelerometer(AnalogInput* channel);
+  explicit AnalogAccelerometer(std::shared_ptr<AnalogInput> channel);
+  virtual ~AnalogAccelerometer() = default;
+
+  float GetAcceleration() const;
+  void SetSensitivity(float sensitivity);
+  void SetZero(float zero);
+  double PIDGet() override;
+
+  void UpdateTable() override;
+  void StartLiveWindowMode() override;
+  void StopLiveWindowMode() override;
+  std::string GetSmartDashboardType() const override;
+  void InitTable(std::shared_ptr<ITable> subTable) override;
+  std::shared_ptr<ITable> GetTable() const override;
+
+ private:
+  void InitAccelerometer();
+
+  std::shared_ptr<AnalogInput> m_analogInput;
+  float m_voltsPerG = 1.0;
+  float m_zeroGVoltage = 2.5;
+
+  std::shared_ptr<ITable> m_table;
+};