feat(futil): Adding back copy_file_tree
feat(futil): Adding back copy_file_tree

I have found a major case where the distutils.copy_tree function fails whenever someone deletes the destination folder and then uses distutils.copy_tree to copy something to that location. The function that I am adding here has always worked for all of the cases I have tested it in.  It also saves us from having to use the prepare_dir method on the parent folder before we copy it.
boris-p/ladybug,boris-p/ladybug