added <> NULL to getLineage call. Prevents recurring events from wiping out other events with null recurId's within their span

docs/changelog/7.x.x.txt

@@ -1,4 +1,7 @@
 7.3.16
+ - fix: Calendar Events Disappearing
+	 http://www.plainblack.com/bugs/tracker/calendar-events-disappearing
+ - fix: Modified SQLForm.pm to handle MySQL null dates.  Undefs them.  Undef dates default to time(), i.e. today's date
  - fix: Thread template: next.url and previous.url tmpl_vars are always defined (Yung Han Khoe, United Knowledge)
  - fix: The POD of Form::Image is faulty (perlDreamer Consulting, LLC)
  - fix: Method name clash between WebGUI::Asset::Post::Thread and WebGUI::AssetVersioning (perlDreamer Consulting, LLC)

lib/WebGUI/Asset/Event.pm

@@ -1433,9 +1433,8 @@ sub processPropertiesFromFormPost {
                     returnObjects       => 1,
                     includeOnlyClasses  => ['WebGUI::Asset::Event'],
                     joinClass           => 'WebGUI::Asset::Event',
-                    whereClause         => qq{Event.recurId = "$old_id"},
+                    whereClause         => qq{Event.recurId = "$old_id" and Event.recurId <> NULL}, #without the <> NULL, it pulls in the recurId's
                 });
-            
             $_->purge for @$events;
         }
         else {