#1 Don't write to freed memory

[David Turner]

Don't write to freed memory -- if for no other reason than that it causes valgrind to complain.

diff old/pyavl-1.1/avl.c new/pyavl-1.1/avl.c
2526d2525
< (*iter->tree->dealloc) (iter);
2527a2527

    avl_dealloc_func dealloc = iter->tree->dealloc;

2528a2529
(*dealloc) (iter);