WinRT apps can set a default, preferred orientation via a .appxmanifest file.
SDL was overriding this on app startup, and making the app use all possible
orientations (landscape and portrait).
Thanks to Eric Wing for the heads up on this!
Attributes on the host device's rotation were getting applied to offscreen
textures in an invalid manner. This was causing some apps to look different,
depending on how the device was rotated.
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
An existing hint lets apps that don't need the timer resolution changed avoid
this, to save battery, etc, but this fixes several problems in timing, audio
callbacks not firing fast enough, etc.
Fixes Bugzilla #2944.
