Alex Szpakowski
SDL's code for exposing the accelerometer as a joystick on iOS currently uses UIAccelerometer, which was superseded by the CoreMotion framework and deprecated since iOS 5.
The UIAccelerometer code still works (for now), but it also throws deprecation warnings whenever SDL is built for iOS, since SDL's deployment target is no longer below iOS 5.
I've created a patch which replaces the old UIAccelerometer code with a replacement based on the CoreMotion framework. It has identical functionality (to SDL users), however iOS apps are now required to link to the CoreMotion framework when using SDL.
It was simpler to just have the polling (actually: hotplug detection)
functions return immediately if it's not an appropriate time to poll.
Note that previously, if any joystick/controller was opened, we would poll
every time anyhow, skipping this function.
