[gtk+] Improve the GTK_STYLE_PROVIDER_PRIORITY_FALLBACK docs

[Matthias Clasen <matthiasc src gnome org>]

commit 0d8c1c9c0992525d2a3250df65c9b5300e33c5ba
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue May 13 11:19:49 2014 -0400

    Improve the GTK_STYLE_PROVIDER_PRIORITY_FALLBACK docs
    
    Explain possible gotcha with catch-all rules.

 gtk/gtkstyleprovider.h |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkstyleprovider.h b/gtk/gtkstyleprovider.h
index ef5c355..a33ce43 100644
--- a/gtk/gtkstyleprovider.h
+++ b/gtk/gtkstyleprovider.h
@@ -40,6 +40,11 @@ G_BEGIN_DECLS
  *
  * The priority used for default style information
  * that is used in the absence of themes.
+ *
+ * Note that this is not very useful for providing default
+ * styling for custom style classes - themes are likely to
+ * override styling provided at this priority with
+ * catch-all `* {...}` rules.
  */
 #define GTK_STYLE_PROVIDER_PRIORITY_FALLBACK      1