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/simulation/SimContinuousOutput.h

@@ -0,0 +1,46 @@
+/*----------------------------------------------------------------------------*/
+/* 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#ifndef _SIM_SPEED_CONTROLLER_H
+#define _SIM_SPEED_CONTROLLER_H
+
+#ifdef _WIN32
+// Ensure that Winsock2.h is included before Windows.h, which can get
+// pulled in by anybody (e.g., Boost).
+#include <Winsock2.h>
+#endif
+
+#include <gazebo/transport/transport.hh>
+#include "SpeedController.h"
+
+using namespace gazebo;
+
+class SimContinuousOutput {
+ private:
+  transport::PublisherPtr pub;
+  float speed;
+
+ public:
+  SimContinuousOutput(std::string topic);
+
+  /**
+   * Set the output value.
+   *
+   * The value is set using a range of -1.0 to 1.0, appropriately
+   * scaling the value.
+   *
+   * @param value The value between -1.0 and 1.0 to set.
+   */
+  void Set(float value);
+
+  /**
+   * @return The most recently set value.
+   */
+  float Get();
+};
+
+#endif