default to returning a flat list of matches. subtree-related fixes to scan
function

operators to Match class so it can be ordered. Protect Match attributes via
@property

mutate canonical version

for which an optional variable is not present

actually exist on disk (and corrsepond to files).

Includes now a tutorial on the FileTree format

are read-only, so we needd to create copies.

data. Will prpbably need tweaking.

guessing the data type of a file/directory path.