Merge: lib/trees: more services and documentation
authorJean Privat <jean@pryen.org>
Thu, 29 Oct 2015 19:03:55 +0000 (15:03 -0400)
committerJean Privat <jean@pryen.org>
Thu, 29 Oct 2015 19:03:55 +0000 (15:03 -0400)
Add `depth` and `Comparable` services to abstract Trees.

Also enhance the abstract_tree module documentation.

Pull-Request: #1787
Reviewed-by: Jean Privat <jean@pryen.org>


Trivial merge