QInputContext doesn't support sending QKeyEvents

QInputContext has method sendEvent(QInputMethodEvent&). When implementing a virtual keyboard the input method event will not be enough. Even when backspace is needed, QKeyEvent is the only option. QCoreApplication::sendEvent(focusWidget()) can be used for that, but it could be cleaner to have support for this similar to QIME. Minor detail, though. Only real implications could be if input context chaining is used.