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/BuiltInAccelerometer.h

@@ -0,0 +1,43 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2014-2016. 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 "LiveWindow/LiveWindowSendable.h"
+#include "SensorBase.h"
+#include "interfaces/Accelerometer.h"
+
+#include <memory>
+
+/**
+ * Built-in accelerometer.
+ *
+ * This class allows access to the RoboRIO's internal accelerometer.
+ */
+class BuiltInAccelerometer : public Accelerometer,
+                             public SensorBase,
+                             public LiveWindowSendable {
+ public:
+  BuiltInAccelerometer(Range range = kRange_8G);
+  virtual ~BuiltInAccelerometer() = default;
+
+  // Accelerometer interface
+  virtual void SetRange(Range range) override;
+  virtual double GetX() override;
+  virtual double GetY() override;
+  virtual double GetZ() override;
+
+  virtual std::string GetSmartDashboardType() const override;
+  virtual void InitTable(std::shared_ptr<ITable> subtable) override;
+  virtual void UpdateTable() override;
+  virtual std::shared_ptr<ITable> GetTable() const override;
+  virtual void StartLiveWindowMode() override {}
+  virtual void StopLiveWindowMode() override {}
+
+ private:
+  std::shared_ptr<ITable> m_table;
+};