specify GL_GLEXT_PROTOTYPES in build environment

SConstruct

@@ -1,6 +1,6 @@
 
 # vim:filetype=python
 
-env = Environment(LIBS = ['GL'], CXXFLAGS = ['-Wall'])
+env = Environment(LIBS = ['GL'], CXXFLAGS = ['-Wall', '-DGL_GLEXT_PROTOTYPES'])
 
 env.Program('driver', Glob('*.cc'))

WFObj.cc

@@ -1,6 +1,4 @@
 
-#define GL_GLEXT_PROTOTYPES
-
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>