Move CameraServer and WPILib headers into their own folder

The old headers were moved into folders because doing so avoids polluting
the system include directories.

Folder names were also normalized to lowercase.

wpilibc/src/main/native/include/frc/BuiltInAccelerometer.h

@@ -0,0 +1,60 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2014-2018 FIRST. 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 "frc/ErrorBase.h"
+#include "frc/interfaces/Accelerometer.h"
+#include "frc/smartdashboard/SendableBase.h"
+
+namespace frc {
+
+/**
+ * Built-in accelerometer.
+ *
+ * This class allows access to the roboRIO's internal accelerometer.
+ */
+class BuiltInAccelerometer : public ErrorBase,
+                             public SendableBase,
+                             public Accelerometer {
+ public:
+  /**
+   * Constructor.
+   *
+   * @param range The range the accelerometer will measure
+   */
+  explicit BuiltInAccelerometer(Range range = kRange_8G);
+
+  // Accelerometer interface
+  /**
+   * Set the measuring range of the accelerometer.
+   *
+   * @param range The maximum acceleration, positive or negative, that the
+   *              accelerometer will measure. Not all accelerometers support all
+   *              ranges.
+   */
+  void SetRange(Range range) override;
+
+  /**
+   * @return The acceleration of the roboRIO along the X axis in g-forces
+   */
+  double GetX() override;
+
+  /**
+   * @return The acceleration of the roboRIO along the Y axis in g-forces
+   */
+  double GetY() override;
+
+  /**
+   * @return The acceleration of the roboRIO along the Z axis in g-forces
+   */
+  double GetZ() override;
+
+  void InitSendable(SendableBuilder& builder) override;
+};
+
+}  // namespace frc