UWP rework (#1231)

* First draft of UWP rework.

* Read desc

- Moved UWP specific functions to uwp_events.h
- Removed BaseApp.
- Implemented example UWP lifecycle.

* Added GIF recording and screenshot support.

* Character inputs and filesystem stuff

* Fix game closing on Xbox when B is pressed.

* Fix the gamepad binding hack

* Add as many keys as I believe are possible.

* Implemented mouse locking of a sort.

* Remove rogue todo, the rest are for a game dev using this example.

* Implemented touch how I "think" it should work. I cant test this.

* Review.

src/rlgl.h

@@ -663,6 +663,7 @@ RLAPI int GetPixelDataSize(int width, int height, int format);// Get pixel data
 #endif
 
 #if defined(GRAPHICS_API_OPENGL_ES2)
+    #define GL_GLEXT_PROTOTYPES
     #include <EGL/egl.h>                // EGL library
     #include <GLES2/gl2.h>              // OpenGL ES 2.0 library
     #include <GLES2/gl2ext.h>           // OpenGL ES 2.0 extensions library