Also, add `#:skip-filtered-directory?` to `find-files`.
Less significantly, adjust `pathlist-closure` to be consistent in the
way that it includes a separator at the end of a directory path.
Also, strengthen the checking that `#:permissive?` (off by default)
performs for `untar` and `untgz` to disallow a link whose target is an
absolute path or has an up-directory element.
Support PNG-encoded icons in ".ico" files and executables.
For executables, instead of supporting only new icons that match the
sizes and encodings of existing icons in an executable, support
arbitrary replacement icons in an executable.
The improved funcitonality relies on a new library (currently
private) for general updates to a Windows executable's
resources.
