title: Error while compiling Open Frameworks on Ubuntu 18.04
body: <p>I am trying to compile OF on Ubuntu 18.04. I installed the dependencies without any problem. The issue seems to come from glew.h and glext.h :</p>
  
  <pre><code>makefileCommon/compile.core.mk:238: recipe for target '/home/XXX/Téléchargements/of_v0.10.1_linux64gcc6_release/libs/openFrameworksCompiled/lib/linux64/obj/Debug/libs/openFrameworks/3d/of3dPrimitives.o' failed
  make[1]: *** [/home/XXX/Téléchargements/of_v0.10.1_linux64gcc6_release/libs/openFrameworksCompiled/lib/linux64/obj/Debug/libs/openFrameworks/3d/of3dPrimitives.o] Error 1
  makefileCommon/compile.core.mk:212: recipe for target 'Debug' failed
  make: *** [Debug] Error 2
  there has been a problem compiling Debug OF library
  please report this problem in the forums
  </code></pre>
  
  <p>And I have a lot of error like that : </p>
  
  <pre><code>In file included from /home/XXX/Téléchargements/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/utils/ofConstants.h:212:0,
               from /home/XXX/Téléchargements/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/3d/ofMesh.h:6,
               from /home/XXX/Téléchargements/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/3d/of3dPrimitives.h:3,
               from /home/XXX/Téléchargements/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/3d/of3dPrimitives.cpp:9:
  /usr/include/GL/glext.h:12099:90: error: 'void __glewGetFragmentMaterialivSGIX(GLenum, GLenum, GLint*)' redeclared as different kind of symbol
   GLAPI void APIENTRY glGetFragmentMaterialivSGIX (GLenum face, GLenum pname, GLint *params);
  
  In file included from /home/XXX/Téléchargements/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/utils/ofConstants.h:210:0,
               from /home/XXX/Téléchargements/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/3d/ofMesh.h:6,
               from /home/XXX/Téléchargements/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/3d/of3dPrimitives.h:3,
               from /home/XXX/Téléchargements/of_v0.10.1_linux64gcc6_release/libs/openFrameworks/3d/of3dPrimitives.cpp:9:
  /usr/include/GL/glew.h:19357:52: note: previous declaration 'void (* __glewGetFragmentMaterialivSGIX)(GLenum, GLenum, const GLint*)'
   GLEW_FUN_EXPORT PFNGLGETFRAGMENTMATERIALIVSGIXPROC __glewGetFragmentMaterialivSGIX;
  </code></pre>
  
  <p>I didn't touch those files so please share your ideas on why the compilation fails !</p>