Comment 7 for bug 635934

I've been talking about GUI issues, but the cause of the MIDI problems stems from WPushButton setting the ControlPushButton::setToggleButton(true) which changes the way the control handles values coming from MIDI devices (as Guy mentions in the bug description).

My workaround in #6 will allow WPushButton to check for the <PushButton> child of <Connection> and not set that ControlPushButton as a toggle button.