[clutter] docs: Add missing clutter_interval_is_valid symbol

[Emmanuele Bassi <ebassi src gnome org>]

commit 847f9aef43b6f42a84b9b894acd5816aadc3ec79
Author: Emmanuele Bassi <ebassi linux intel com>
Date:   Sun Jun 10 23:33:00 2012 +0100

    docs: Add missing clutter_interval_is_valid symbol

 doc/reference/clutter/clutter-sections.txt |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/doc/reference/clutter/clutter-sections.txt b/doc/reference/clutter/clutter-sections.txt
index c7617c9..705f853 100644
--- a/doc/reference/clutter/clutter-sections.txt
+++ b/doc/reference/clutter/clutter-sections.txt
@@ -1869,6 +1869,7 @@ clutter_interval_set_initial
 clutter_interval_set_final
 
 <SUBSECTION>
+clutter_interval_is_valid
 clutter_interval_validate
 clutter_interval_compute_value
 clutter_interval_compute