[folks] docs: Clarify use of interfaces for property access on Folks.Persona

[Philip Withnall <pwithnall src gnome org>]

commit 2210c05ddd7df0ae3a3131222f8b8720bf5e31bc
Author: Philip Withnall <philip tecnocode co uk>
Date:   Sat Jun 22 00:00:41 2013 +0100

    docs: Clarify use of interfaces for property access on Folks.Persona

 folks/persona.vala |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)
---
diff --git a/folks/persona.vala b/folks/persona.vala
index 090df82..f08d237 100644
--- a/folks/persona.vala
+++ b/folks/persona.vala
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2010 Collabora Ltd.
+ * Copyright (C) 2013 Philip Withnall
  *
  * This library is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published by
@@ -16,6 +17,7 @@
  *
  * Authors:
  *       Travis Reitter <travis reitter collabora co uk>
+ *       Philip Withnall <philip tecnocode co uk>
  */
 
 using GLib;
@@ -68,6 +70,13 @@ public errordomain Folks.PropertyError
  *
  * All the personas belonging to one physical person are aggregated to form a
  * single { link Individual} representing that person.
+ *
+ * Properties of a persona are provided by implementing "details" interfaces,
+ * such as { link NameDetails} or { link EmailDetails}. They must be accessed
+ * through these interfaces. Different backends' subclasses of { link Persona}
+ * may implement different sets of interfaces. The set of interfaces implemented
+ * by a given persona is guaranteed not to change over the lifetime of that
+ * persona.
  */
 public abstract class Folks.Persona : Object
 {