Added imm.h include, will be needed on MinGW.

Changed comment to c-style and removed some end-of-line whitespace.

src/video/win32/SDL_win32video.h

@@ -37,6 +37,7 @@
 #include <windows.h>
 
 #include <msctf.h>
+#include <imm.h>
 
 #if SDL_VIDEO_RENDER_D3D
 //#include <d3d9.h>
@@ -81,7 +82,7 @@ typedef struct
     void *data;
 } TSFSink;
 
-// Definition from Win98DDK version of IMM.H
+/* Definition from Win98DDK version of IMM.H */
 typedef struct tagINPUTCONTEXT2 {
     HWND                hWnd;
     BOOL                fOpen;