Support for continuous feedback through QFeedbackEffect

Qt Mobility QFeedbackEffect supports supports playing instant feedbacks defined in QFeedbackEffect::ThemeEffect. Playing different continuous feedback types on the other hand is not supported. Symbian supports five types of continuous feedbacks: smooth, slider, dynamic slider, input and flick. Of these, only the generic type smooth is played with the current implementation of Symbian feedback plugin. The interface for QFeedbackEffect lacks the kind of convenient way for triggering continuous feedbacks it offers for ThemeEffects (playThemeEffect). It would be great if one could call for example QFeedbackEffect::continuousTriggered(ContinuousEffect effect) and QFeedbackEffect::continuousStopped(ContinuousEffect effect). This functionality would then be applicable on QML side as well.