Description: replace deprecated STR2CSTR by StringValuePtr
 http://www.ruby-forum.com/topic/215406
Author: Cédric Boutillier <cedric.boutillier@gmail.com>
Last-Update: 2011-12-20

--- a/ext/glut/glut.c
+++ b/ext/glut/glut.c
@@ -93,7 +93,7 @@
 	largc = RARRAY_LEN(orig_arg);
 	largv = ALLOCA_N(char*, largc);
 	for (i = 0; i < largc; i++)
-		largv[i] = STR2CSTR(RARRAY_PTR(orig_arg)[i]);
+		largv[i] = StringValuePtr(RARRAY_PTR(orig_arg)[i]);
 	
 	glutInit(&largc, largv);