Turn on line antialiasing (requires blending to be enabled)

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%403355

src/video/SDL_renderer_gl.c

@@ -425,6 +425,7 @@ GL_CreateRenderer(SDL_Window * window, Uint32 flags)
     data->scaleMode = -1;
     data->glDisable(GL_DEPTH_TEST);
     data->glDisable(GL_CULL_FACE);
+    data->glEnable(GL_LINE_SMOOTH);
     if (data->GL_ARB_texture_rectangle_supported) {
         data->glEnable(GL_TEXTURE_RECTANGLE_ARB);
     } else {