Eliminate normpath from foldmap calls.
Normcase already takes care of upper/lower case and /->\ conversions.
What's left for normpath is folding of a/../a sequences but this should
be either done consistently on both non-folding and folding code path
or not at all, otherwise we are introducing inconsistent behavior between the
two that has nothing to do with case folding.
Second argument against it - normpath being pure Python function is very slow -
as much as 50% of time is spend just inside normpath call on my repository.