Added final changes to CHANGES.rst
Add DRAFT node in model testdata.
Added tests for duplicate slugs
Fix `Page.objects.best_match_for_path('/path/without-slash')`

Found while writing unit tests for `get_for_path()` and `best_match_for_path()`.
This likely doesn't affect anything yet, as the URL dispatcher uses
get_for_path() first, which would return the page already.
Fixed generated URL path for "file" node types in sub folders.

Added unit tests for file-type nodes.