Removed BlogTreeExtension in favour of the new WidgetPageExtension
in the "widgets module". Use the following code to update:
Object::add_extension('BlogTree', 'WidgetPageExtension');
Object::add_extension('BlogEntry', 'WidgetPageExtension');
The template placeholder has been renamed from $SideBar to
$SideBarView. In case you're overriding blog templates,
please adjust accordingly.
This change means that widgets can theoretically be applied
to individual blog entries as well, since they need the
"SideBar" relationship as well. In practice, this defaults
to "InheritSideBar" though, which pulls them from the BlogHolder as usual.
It was disabled since migrating the module to SS3,
and the whole concept has become less relevant since spammers discovered trackbacks
(ref http://en.wikipedia.org/wiki/Trackback#Spam).
Since we don't have the resources to make a spam-proof trackback system,
its prudent to remove it instead.
