[glib] Doc: clarify set_property() vfunc

[Sébastien Wilmet <swilmet src gnome org>]

commit e3c2d030922d1cab1eab45d3695622ccf0a736e6
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Thu Mar 14 23:24:18 2013 +0100

    Doc: clarify set_property() vfunc
    
    Implementations "don't need to ...". It was not clear what happen
    if they do it all the same.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=695887

 gobject/gobject.h |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)
---
diff --git a/gobject/gobject.h b/gobject/gobject.h
index 2c58f72..9ca0ade 100644
--- a/gobject/gobject.h
+++ b/gobject/gobject.h
@@ -257,9 +257,10 @@ struct  _GObject
  *  @constructor of the parent class. Overriding @constructor should be rarely 
  *  needed, e.g. to handle construct properties, or to implement singletons.
  * @set_property: the generic setter for all properties of this type. Should be
- *  overridden for every type with properties. Implementations of @set_property
- *  don't need to emit property change notification explicitly, this is handled
- *  by the type system.
+ *  overridden for every type with properties. If implementations of
+ *  @set_property don't emit property change notification explicitly, this will
+ *  be done implicitly by the type system. However, if the notify signal is
+ *  emitted explicitly, the type system will not emit it a second time.
  * @get_property: the generic getter for all properties of this type. Should be
  *  overridden for every type with properties.
  * @dispose: the @dispose function is supposed to drop all references to other