[wpilib] PWMSpeedController.get(): Apply Inversion (#3016)

This makes get() return the value actually sent to the motor.

This is a breaking change.

wpilibc/src/main/native/cpp/PWMSpeedController.cpp

@@ -13,7 +13,7 @@ void PWMSpeedController::Set(double speed) {
 }
 
 double PWMSpeedController::Get() const {
-  return GetSpeed();
+  return GetSpeed() * (m_isInverted ? -1.0 : 1.0);
 }
 
 void PWMSpeedController::SetInverted(bool isInverted) {

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

@@ -28,7 +28,9 @@ class PWMSpeedController : public PWM, public SpeedController {
   void Set(double value) override;
 
   /**
-   * Get the recently set value of the PWM.
+   * Get the recently set value of the PWM. This value is affected by the
+   * inversion property. If you want the value that is sent directly to the
+   * SpeedController, use {@link PWM#getSpeed()} instead.
    *
    * @return The most recently set value for the PWM between -1.0 and 1.0.
    */