Removed Windows CE support from SDL 2.0.

It's a long-dead platform, and we don't have any way to build for, test, or
maintain it, so there's no sense in doing acrobatics to support it.

If you need Windows CE support, use SDL 1.2. If you need Windows Phone support,
send SDL 2.0 patches for the newer Windows Mobile platform.

include/SDL_thread.h

@@ -86,9 +86,7 @@ typedef int (SDLCALL * SDL_ThreadFunction) (void *data);
  *  library!
  */
 #define SDL_PASSED_BEGINTHREAD_ENDTHREAD
-#ifndef _WIN32_WCE
 #include <process.h>            /* This has _beginthread() and _endthread() defined! */
-#endif
 
 typedef uintptr_t(__cdecl * pfnSDL_CurrentBeginThread) (void *, unsigned,
                                                         unsigned (__stdcall *
@@ -106,21 +104,11 @@ SDL_CreateThread(SDL_ThreadFunction fn, const char *name, void *data,
                  pfnSDL_CurrentBeginThread pfnBeginThread,
                  pfnSDL_CurrentEndThread pfnEndThread);
 
-#if defined(_WIN32_WCE)
-
-/**
- *  Create a thread.
- */
-#define SDL_CreateThread(fn, name, data) SDL_CreateThread(fn, name, data, NULL, NULL)
-
-#else
-
 /**
  *  Create a thread.
  */
 #define SDL_CreateThread(fn, name, data) SDL_CreateThread(fn, name, data, _beginthreadex, _endthreadex)
 
-#endif
 #else
 
 /**