Added SDL_SetWindowResizable(). (thanks, Ethan!)

--HG--
extra : rebase_source : a1929f1de6844265f3744a87384620703f960de9

include/SDL_video.h

@@ -83,6 +83,7 @@ typedef struct
  *  \sa SDL_SetWindowPosition()
  *  \sa SDL_SetWindowSize()
  *  \sa SDL_SetWindowBordered()
+ *  \sa SDL_SetWindowResizable()
  *  \sa SDL_SetWindowTitle()
  *  \sa SDL_ShowWindow()
  */
@@ -706,6 +707,23 @@ extern DECLSPEC void SDLCALL SDL_GetWindowMaximumSize(SDL_Window * window,
 extern DECLSPEC void SDLCALL SDL_SetWindowBordered(SDL_Window * window,
                                                    SDL_bool bordered);
 
+/**
+ *  \brief Set the user-resizable state of a window.
+ *
+ *  This will add or remove the window's SDL_WINDOW_RESIZABLE flag and
+ *  allow/disallow user resizing of the window. This is a no-op if the
+ *  window's resizable state already matches the requested state.
+ *
+ *  \param window The window of which to change the resizable state.
+ *  \param resizable SDL_TRUE to allow resizing, SDL_FALSE to disallow.
+ *
+ *  \note You can't change the resizable state of a fullscreen window.
+ *
+ *  \sa SDL_GetWindowFlags()
+ */
+extern DECLSPEC void SDLCALL SDL_SetWindowResizable(SDL_Window * window,
+                                                    SDL_bool resizable);
+
 /**
  *  \brief Show a window.
  *