Also made small fixes to trees that contained invalid characters

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

It's called kurt rather than MK

reverting back

needed for python 3.5