progs/tests: compile with SCons and glew

Also get mingw cross-compilation of these tests working

progs/tests/prog_parameter.c

@@ -35,6 +35,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <math.h>
+#include <GL/glew.h>
 #include <GL/glut.h>
 
 #ifndef GL_EXT_gpu_program_parameters
@@ -274,6 +275,7 @@ int main( int argc, char *argv[] )
    glutInitWindowSize( Width, Height );
    glutInitDisplayMode( GLUT_RGB );
    glutCreateWindow( "Program Parameters Test" );
+   glewInit();
    glutReshapeFunc( Reshape );
    glutKeyboardFunc( Key );
    glutDisplayFunc( Display );