gl: initialise Glew in the video setup instead of the SDL app, so we don't

have to duplicate this code to other places. Fixes the GTK app on the way.

src/sdlapp.cpp

@@ -59,15 +59,6 @@ SdlApp::SdlApp(char const *title, vec2i res, float fps) :
         SDL_Quit();
         exit(EXIT_FAILURE);
     }
-#if defined USE_GLEW
-    GLenum glerr = glewInit();
-    if (glerr != GLEW_OK)
-    {
-        Log::Error("cannot initialise GLEW: %s\n", glewGetErrorString(glerr));
-        SDL_Quit();
-        exit(EXIT_FAILURE);
-    }
-#endif
 
     SDL_WM_SetCaption(title, NULL);
     SDL_ShowCursor(0);

src/video.cpp

@@ -51,6 +51,16 @@ vec2i VideoData::saved_viewport = 0;
 
 void Video::Setup(vec2i size)
 {
+#if defined USE_GLEW
+    /* Initialise GLEW if necessary */
+    GLenum glerr = glewInit();
+    if (glerr != GLEW_OK)
+    {
+        Log::Error("cannot initialise GLEW: %s\n", glewGetErrorString(glerr));
+        exit(EXIT_FAILURE);
+    }
+#endif
+
     /* Initialise OpenGL */
     glViewport(0, 0, size.x, size.y);