[ios] - always send a speed change to ios when the player gets paused (to stop the playback progress bar in the ios control center)
[ios] - allow usage of IDispResource on the whole darwin platform (not only osx)
[ios] - allow to register IDispResource on iOS Windowing and call OnAppFocusChange when needed
[ios] - call OnAppFocusChange in windowing when app is backgrounded/foregrounded on ios