filetree 1.0.0

A simple tree structure for working with FilePath objects in ruby. I simply took the simple_tree module from https://github.com/ealdent/simple-tree and hacked it into Pathname (http://www.ruby-doc.org/stdlib-2.0/libdoc/pathname/rdoc/Pathname.html) from the std-lib. This means you get all the awesome features of working with Pathname, as well as making it easy to examine a filepath's ancestors and descendants.