Build hidapi code into SDL as a new public API

This prevents conflicts with hidapi linked with applications, as well as allowing applications to make use of HIDAPI on Android and other platforms that might not normally have an implementation available.

VisualC-WinRT/SDL-UWP.vcxproj

@@ -47,6 +47,7 @@
     <ClInclude Include="..\include\SDL_filesystem.h" />
     <ClInclude Include="..\include\SDL_haptic.h" />
     <ClInclude Include="..\include\SDL_hints.h" />
+    <ClInclude Include="..\include\SDL_hidapi.h" />
     <ClInclude Include="..\include\SDL_input.h" />
     <ClInclude Include="..\include\SDL_joystick.h" />
     <ClInclude Include="..\include\SDL_keyboard.h" />
@@ -113,6 +114,7 @@
     <ClInclude Include="..\src\haptic\windows\SDL_dinputhaptic_c.h" />
     <ClInclude Include="..\src\haptic\windows\SDL_windowshaptic_c.h" />
     <ClInclude Include="..\src\haptic\windows\SDL_xinputhaptic_c.h" />
+    <ClInclude Include="..\src\hidapi\SDL_hidapi.c" />
     <ClInclude Include="..\src\joystick\SDL_gamecontrollerdb.h" />
     <ClInclude Include="..\src\joystick\SDL_joystick_c.h" />
     <ClInclude Include="..\src\joystick\SDL_sysjoystick.h" />
@@ -592,4 +594,4 @@
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
+</Project>

VisualC-WinRT/SDL-UWP.vcxproj.filters

@@ -69,6 +69,9 @@
     <ClInclude Include="..\include\SDL_hints.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="..\include\SDL_hidapi.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
     <ClInclude Include="..\include\SDL_input.h">
       <Filter>Header Files</Filter>
     </ClInclude>
@@ -539,6 +542,9 @@
     <ClCompile Include="..\src\haptic\SDL_haptic.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\src\hidapi\SDL_hidapi.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\src\joystick\dummy\SDL_sysjoystick.c">
       <Filter>Source Files</Filter>
     </ClCompile>