match: consider filesets as "anypats"
Matt suggested this on IRC, I do not think the choice is obvious, but this one
makes things simpler because while filesets are turned into a list of files
into the match objects, it would more be difficult to tell invalid files passed
in pats from those expanded from filesets.
workingfilectx.date = (1000, 0)
ASCII : Gr?ezi!
Latin-1 : Grüezi!
UTF-8 : Grüezi!