added optional prefix and buildroot args (for RPM)

tools/sugar-setup-activity.in

@@ -3,8 +3,18 @@ import sys
 
 from sugar import setup
 
+if len(sys.argv) > 2:
+	prefix = sys.argv[2]
+else:
+	prefix = '@prefix@'
+
+if len(sys.argv) > 3:
+	root = sys.argv[3]
+else:
+	root = ''
+
 setup.setup_activity(sys.argv[1],
-		     '@prefix@/share/sugar/activities',
-		     '@prefix@/bin/sugar-activity-factory')
+		     '%s%s/share/sugar/activities' % (root, prefix),
+		     '%s/bin/sugar-activity-factory' % prefix)
 
 print '%s installed.' % sys.argv[1]