Avoid snapshotting uncreatable loggable classes.

Timeline/Loggable.C

@@ -341,7 +341,8 @@ Loggable::snapshot( const char *file )
 
     for ( int i = 0; i < _log_id; ++i )
     {
-        _loggables[ i ]->log_create();
+        if ( _class_map[ string( _loggables[ i ]->class_name() ) ] )
+            _loggables[ i ]->log_create();
     }
 
     fclose( _fp );

Timeline/Sequence.H

@@ -43,7 +43,6 @@ class Sequence_Widget;
 class Sequence : public Fl_Widget, public Loggable
 {
 
-
     static queue <Sequence_Widget *> _delete_queue;
 
 protected: