Create VideoCamera base class and move camera settings functions to it.

This makes them available for both UsbCamera and HttpCamera / AxisCamera.

To avoid virtual functions in the public-facing interface, move the
implementation of the camera settings functions to the core library.

java/src/edu/wpi/cscore/VideoCamera.java

@@ -0,0 +1,63 @@
+/*----------------------------------------------------------------------------*/
+/* 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+package edu.wpi.cscore;
+
+/// A source that represents a video camera.
+public class VideoCamera extends VideoSource {
+  public class WhiteBalance {
+    public static final int kFixedIndoor = 3000;
+    public static final int kFixedOutdoor1 = 4000;
+    public static final int kFixedOutdoor2 = 5000;
+    public static final int kFixedFluorescent1 = 5100;
+    public static final int kFixedFlourescent2 = 5200;
+  }
+
+  protected VideoCamera(int handle) {
+    super(handle);
+  }
+
+  /// Set the brightness, as a percentage (0-100).
+  public synchronized void setBrightness(int brightness) {
+    CameraServerJNI.setCameraBrightness(m_handle, brightness);
+  }
+
+  /// Get the brightness, as a percentage (0-100).
+  public synchronized int getBrightness() {
+    return CameraServerJNI.getCameraBrightness(m_handle);
+  }
+
+  /// Set the white balance to auto.
+  public synchronized void setWhiteBalanceAuto() {
+    CameraServerJNI.setCameraWhiteBalanceAuto(m_handle);
+  }
+
+  /// Set the white balance to hold current.
+  public synchronized void setWhiteBalanceHoldCurrent() {
+    CameraServerJNI.setCameraWhiteBalanceHoldCurrent(m_handle);
+  }
+
+  /// Set the white balance to manual, with specified color temperature.
+  public synchronized void setWhiteBalanceManual(int value) {
+    CameraServerJNI.setCameraWhiteBalanceManual(m_handle, value);
+  }
+
+  /// Set the exposure to auto aperture.
+  public synchronized void setExposureAuto() {
+    CameraServerJNI.setCameraExposureAuto(m_handle);
+  }
+
+  /// Set the exposure to hold current.
+  public synchronized void setExposureHoldCurrent() {
+    CameraServerJNI.setCameraExposureHoldCurrent(m_handle);
+  }
+
+  /// Set the exposure to manual, as a percentage (0-100).
+  public synchronized void setExposureManual(int value) {
+    CameraServerJNI.setCameraExposureManual(m_handle, value);
+  }
+}