WinRT: build fixes

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.

VisualC-WinRT/WinRT81_VS2013/SDL-WinRT81.vcxproj

@@ -131,6 +131,7 @@
     <ClInclude Include="..\..\src\render\software\SDL_render_sw_c.h" />
     <ClInclude Include="..\..\src\render\software\SDL_rotate.h" />
     <ClInclude Include="..\..\src\SDL_assert_c.h" />
+    <ClInclude Include="..\..\src\SDL_dataqueue.h" />
     <ClInclude Include="..\..\src\SDL_error_c.h" />
     <ClInclude Include="..\..\src\SDL_fatal.h" />
     <ClInclude Include="..\..\src\SDL_hints_c.h" />
@@ -262,6 +263,7 @@
     <ClCompile Include="..\..\src\render\software\SDL_rotate.c" />
     <ClCompile Include="..\..\src\SDL.c" />
     <ClCompile Include="..\..\src\SDL_assert.c" />
+    <ClCompile Include="..\..\src\SDL_dataqueue.c" />
     <ClCompile Include="..\..\src\SDL_error.c" />
     <ClCompile Include="..\..\src\SDL_hints.c" />
     <ClCompile Include="..\..\src\SDL_log.c" />

VisualC-WinRT/WinRT81_VS2013/SDL-WinRT81.vcxproj.filters

@@ -393,6 +393,9 @@
     <ClInclude Include="..\..\src\video\winrt\SDL_winrtgamebar_cpp.h">
       <Filter>Source Files</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\src\SDL_dataqueue.h">
+      <Filter>Source Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\..\src\atomic\SDL_atomic.c">
@@ -713,5 +716,8 @@
     <ClCompile Include="..\..\src\video\winrt\SDL_winrtgamebar.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\SDL_dataqueue.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
 </Project>