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/MotorSafetyHelper.h

@@ -19,15 +19,84 @@ class MotorSafety;
 
 class MotorSafetyHelper : public ErrorBase {
  public:
+  /**
+   * The constructor for a MotorSafetyHelper object.
+   *
+   * The helper object is constructed for every object that wants to implement
+   * the Motor Safety protocol. The helper object has the code to actually do
+   * the timing and call the motors Stop() method when the timeout expires. The
+   * motor object is expected to call the Feed() method whenever the motors
+   * value is updated.
+   *
+   * @param safeObject a pointer to the motor object implementing MotorSafety.
+   *                   This is used to call the Stop() method on the motor.
+   */
   explicit MotorSafetyHelper(MotorSafety* safeObject);
+
   ~MotorSafetyHelper();
+
+  /**
+   * Feed the motor safety object.
+   *
+   * Resets the timer on this object that is used to do the timeouts.
+   */
   void Feed();
+
+  /**
+   * Set the expiration time for the corresponding motor safety object.
+   *
+   * @param expirationTime The timeout value in seconds.
+   */
   void SetExpiration(double expirationTime);
+
+  /**
+   * Retrieve the timeout value for the corresponding motor safety object.
+   *
+   * @return the timeout value in seconds.
+   */
   double GetExpiration() const;
+
+  /**
+   * Determine if the motor is still operating or has timed out.
+   *
+   * @return a true value if the motor is still operating normally and hasn't
+   * timed out.
+   */
   bool IsAlive() const;
+
+  /**
+   * Check if this motor has exceeded its timeout.
+   *
+   * This method is called periodically to determine if this motor has exceeded
+   * its timeout value. If it has, the stop method is called, and the motor is
+   * shut down until its value is updated again.
+   */
   void Check();
+
+  /**
+   * Enable/disable motor safety for this device
+   *
+   * Turn on and off the motor safety option for this PWM object.
+   *
+   * @param enabled True if motor safety is enforced for this object
+   */
   void SetSafetyEnabled(bool enabled);
+
+  /**
+   * Return the state of the motor safety enabled flag
+   *
+   * Return if the motor safety is currently enabled for this devicce.
+   *
+   * @return True if motor safety is enforced for this device
+   */
   bool IsSafetyEnabled() const;
+
+  /**
+   * Check the motors to see if any have timed out.
+   *
+   * This static method is called periodically to poll all the motors and stop
+   * any that have timed out.
+   */
   static void CheckMotors();
 
  private: