Use best quality for JPEG images.

--- graph.c.orig	Fri Apr  3 12:02:58 2015
+++ graph.c	Fri Apr  3 12:03:16 2015
@@ -199,7 +199,7 @@ graph_generate_images(struct matrix *matrices)
 			return (1);
 		}
 		if (matrix->type == 0)
-			gdImageJpeg(im, out, 95);
+			gdImageJpeg(im, out, 100);
 		else
 			gdImagePng(im, out);
 		fclose(out);