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/src/AnalogPotentiometer.cpp

@@ -0,0 +1,84 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "AnalogPotentiometer.h"
+
+/**
+ * Common initialization code called by all constructors.
+ */
+void AnalogPotentiometer::initPot(AnalogInput* input, double scale,
+                                  double offset) {
+  m_scale = scale;
+  m_offset = offset;
+  m_analog_input = input;
+}
+
+AnalogPotentiometer::AnalogPotentiometer(int channel, double scale,
+                                         double offset) {
+  m_init_analog_input = true;
+  initPot(new AnalogInput(channel), scale, offset);
+}
+
+AnalogPotentiometer::AnalogPotentiometer(AnalogInput* input, double scale,
+                                         double offset) {
+  m_init_analog_input = false;
+  initPot(input, scale, offset);
+}
+
+AnalogPotentiometer::AnalogPotentiometer(AnalogInput& input, double scale,
+                                         double offset) {
+  m_init_analog_input = false;
+  initPot(&input, scale, offset);
+}
+
+AnalogPotentiometer::~AnalogPotentiometer() {
+  if (m_init_analog_input) {
+    delete m_analog_input;
+    m_init_analog_input = false;
+  }
+}
+
+/**
+ * Get the current reading of the potentiomere.
+ *
+ * @return The current position of the potentiometer.
+ */
+double AnalogPotentiometer::Get() const {
+  return m_analog_input->GetVoltage() * m_scale + m_offset;
+}
+
+/**
+ * Implement the PIDSource interface.
+ *
+ * @return The current reading.
+ */
+double AnalogPotentiometer::PIDGet() { return Get(); }
+
+/**
+ * @return the Smart Dashboard Type
+ */
+std::string AnalogPotentiometer::GetSmartDashboardType() const {
+  return "Analog Input";
+}
+
+/**
+ * Live Window code, only does anything if live window is activated.
+ */
+void AnalogPotentiometer::InitTable(std::shared_ptr<ITable> subtable) {
+  m_table = subtable;
+  UpdateTable();
+}
+
+void AnalogPotentiometer::UpdateTable() {
+  if (m_table != nullptr) {
+    m_table->PutNumber("Value", Get());
+  }
+}
+
+std::shared_ptr<ITable> AnalogPotentiometer::GetTable() const {
+  return m_table;
+}