A negative periodic magnitude doesn't exist in Windows' and MacOS' FF APIs
The periodic magnitude parameter of the SDL Haptic API is based on the Linux
FF API, so it means they are not directly compatible:
'dwMagnitude' is a 'DWORD', which is unsigned.
Fixes Bugzilla #2701.
This modifies SDL_PauseAudio behavior to pause all audio devices instead of
just the default one (required on Android, at least for testmultiaudio on my
Nexus 4 which reported 2 audio devices).
It also changes SDL_PauseAudioDevice to retain the device lock from pause until
resume in order to save battery in mobile devices.
since the window system doesn't do it for us like other platforms.
This prevents sticky keys and missed keys when going in and out
of focus, for example Alt would appear to stick if switching away
from an SDL app with Alt-Tab and had to be pressed again.
CR: Sam
