These fixes are lumped into two categories:
1. add new file, SDL_dataqueue.c, to UWP/WinRT build-inputs (via MSVC project
files)
2. implement a temporary, hack-fix for a build error in SDL_xinputjoystick.c.
Win32's Raw Input APIs are, unfortunately, not available for use in UWP/WinRT
APIs. There does appear to be a replacement API, available in the
Windows.Devices.HumanInterfaceDevice namespace.
This fix should be sufficient to get SDL compiling again, without affecting
Win32 builds, however using the UWP/WinRT API (in UWP/WinRT builds) would
almost certainly be better (for UWP/WinRT builds).
TODO: research Windows.Devices.HumanInterfaceDevice, and use that if and as
appropriate.
This change has also been tested as buildable + runnable on Win32 + MSVC 2015,
2013, 2012, and 2010. It may fix similar build errors (in XInput code) that
are appearing in MingW builds (on buildbot).
The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().
