Support following key event activity with input method

This is a tentative task and needs further discussion.

With MeeGotouch most of the applications are fine with QInputMethodEvents for input. On few occasions some additional information is needed, though. The browser needs to trigger javascript DOM events which are based on key events, but input method with error correction would be nice to have otherwise. The dialer needs to make beeps when hardware keyboard buttons are held down, but also would be better with button long press to secondary character behavior otherwise (implemented by sending QIMEs instead of key events). For these cases we expose additional keyPress and keyRelease signals on MInputMethodState for which the applications can connect to.

Need to figure out if similar interface would make sense on Qt, and should there be also some further connection to QIME. Or should this information be included in QIME. Or if other approaches exist.