Fix default location of where to find ghostscript

--- GSPdf.m.orig	Wed Apr 18 23:58:09 2012
+++ GSPdf.m	Mon Jul  2 19:46:27 2012
@@ -133,7 +133,7 @@ static GSPdf *gspdf = nil;
 #if defined __NetBSD__
     gsPathStr = @"/usr/pkg/bin/gs";
 #else
-    gsPathStr = @"/usr/bin/gs";
+    gsPathStr = @"${LOCALBASE}/bin/gs";
 #endif
     }
   [gsPath release];