minor updates

gramps/plugins/lib/libtreebase.py

@@ -837,6 +837,9 @@ class LineBase(object):
         self.start = [start]
         self.end = []
 
+    def add_from(self, person):
+        self.start.append(person)
+    
     def add_to(self, person):
         """ add destination boxes to draw this line to """
         self.end.append(person)