[gtk+/wip/baseline2] Document GTK_ALIGN_BASELINE

[Alexander Larsson <alexl src gnome org>]

commit 926c50c3f9f78a4b61f95b48bf500cef4f81cb60
Author: Alexander Larsson <alexl redhat com>
Date:   Tue Mar 26 15:41:29 2013 +0100

    Document GTK_ALIGN_BASELINE

 gtk/gtkenums.h |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkenums.h b/gtk/gtkenums.h
index ceac3f1..0ca62d2 100644
--- a/gtk/gtkenums.h
+++ b/gtk/gtkenums.h
@@ -51,6 +51,7 @@ G_BEGIN_DECLS
  *     or top
  * @GTK_ALIGN_CENTER: center natural width of widget inside the
  *     allocation
+ * @GTK_ALIGN_BASELINE: align the widget according to the baseline. Since 3.10.
  *
  * Controls how a widget deals with extra space in a single (x or y)
  * dimension.
@@ -64,6 +65,10 @@ G_BEGIN_DECLS
  *
  * Note that in horizontal context @GTK_ALIGN_START and @GTK_ALIGN_END
  * are interpreted relative to text direction.
+ *
+ * GTK_ALIGN_BASELINE support for it is optional for containers and widgets, and
+ * it is only supported for vertical alignment.  When its not supported by
+ * a child or a container it is treated as @GTK_ALIGN_FILL.
  */
 typedef enum
 {