Moved C++ comments from source files to headers (#1111)

Also sorted functions in C++ sources to match order in related headers.

wpilibc/src/main/native/include/PWMSpeedController.h

@@ -17,17 +17,47 @@ namespace frc {
  */
 class PWMSpeedController : public SafePWM, public SpeedController {
  public:
+  /**
+   * Set the PWM value.
+   *
+   * The PWM value is set using a range of -1.0 to 1.0, appropriately scaling
+   * the value for the FPGA.
+   *
+   * @param speed The speed value between -1.0 and 1.0 to set.
+   */
   void Set(double value) override;
+
+  /**
+   * Get the recently set value of the PWM.
+   *
+   * @return The most recently set value for the PWM between -1.0 and 1.0.
+   */
   double Get() const override;
+
   void SetInverted(bool isInverted) override;
+
   bool GetInverted() const override;
+
   void Disable() override;
+
   void StopMotor() override;
 
+  /**
+   * Write out the PID value as seen in the PIDOutput base object.
+   *
+   * @param output Write out the PWM value as was found in the PIDController
+   */
   void PIDWrite(double output) override;
 
  protected:
+  /**
+   * Constructor for a PWM Speed Controller connected via PWM.
+   *
+   * @param channel The PWM channel that the controller is attached to. 0-9 are
+   *                on-board, 10-19 are on the MXP port
+   */
   explicit PWMSpeedController(int channel);
+
   void InitSendable(SendableBuilder& builder) override;
 
  private: