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/Preferences.h

@@ -0,0 +1,71 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2011-2016. 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 <map>
+#include <string>
+#include <vector>
+#include "ErrorBase.h"
+#include "HAL/cpp/Semaphore.hpp"
+#include "Task.h"
+#include "networktables/NetworkTable.h"
+#include "tables/ITableListener.h"
+
+/**
+ * The preferences class provides a relatively simple way to save important
+ * values to the RoboRIO to access the next time the RoboRIO is booted.
+ *
+ * <p>This class loads and saves from a file inside the RoboRIO.  The user can
+ * not access the file directly, but may modify values at specific fields which
+ * will then be automatically periodically saved to the file by the NetworkTable
+ * server.</p>
+ *
+ * <p>This class is thread safe.</p>
+ *
+ * <p>This will also interact with {@link NetworkTable} by creating a table
+ * called "Preferences" with all the key-value pairs.</p>
+ */
+class Preferences : public ErrorBase {
+ public:
+  static Preferences* GetInstance();
+
+  std::vector<std::string> GetKeys();
+  std::string GetString(llvm::StringRef key, llvm::StringRef defaultValue = "");
+  int GetInt(llvm::StringRef key, int defaultValue = 0);
+  double GetDouble(llvm::StringRef key, double defaultValue = 0.0);
+  float GetFloat(llvm::StringRef key, float defaultValue = 0.0);
+  bool GetBoolean(llvm::StringRef key, bool defaultValue = false);
+  int64_t GetLong(llvm::StringRef key, int64_t defaultValue = 0);
+  void PutString(llvm::StringRef key, llvm::StringRef value);
+  void PutInt(llvm::StringRef key, int value);
+  void PutDouble(llvm::StringRef key, double value);
+  void PutFloat(llvm::StringRef key, float value);
+  void PutBoolean(llvm::StringRef key, bool value);
+  void PutLong(llvm::StringRef key, int64_t value);
+  DEPRECATED(
+      "Saving is now automatically performed by the NetworkTables server.")
+  void Save();
+  bool ContainsKey(llvm::StringRef key);
+  void Remove(llvm::StringRef key);
+
+ protected:
+  Preferences();
+  virtual ~Preferences() = default;
+
+ private:
+  std::shared_ptr<ITable> m_table;
+  class Listener : public ITableListener {
+   public:
+    void ValueChanged(ITable* source, llvm::StringRef key,
+                      std::shared_ptr<nt::Value> value, bool isNew) override;
+    void ValueChangedEx(ITable* source, llvm::StringRef key,
+                        std::shared_ptr<nt::Value> value,
+                        unsigned int flags) override;
+  };
+  Listener m_listener;
+};