libRocket/libRocket — pull request #206 by bruceoutdoors (2014-08-24 14:47:46+00:00)
Title: fixed gl.h compile time errors in VS2013 (SFML2 sample)

according to http://stackoverflow.com/questions/430413/vc-compile-errors-when-including-gl-h the gl.h errors are specific to VC++, there placing a condition there elimates the for VC++ people to uncomment

#include