avoid removal of marginal stuff:
@@ -928,8 +928,6 @@ class TreeAnc(object):
# do clean-up:
if not debug:
for node in self.tree.find_clades():
- #del node.marginal_subtree_LH
- del node.marginal_Lx
del node.marginal_subtree_LH_prefactor
del node.seq_msg_from_parent
