fsobject.fsobject: fix handling of symlinks

When you deleted a symlink to a directory and created a normal directory
with the same name, it still appeared a symlink.  This commit fixes
that.
core.tab: Fix files being treated as dirs after rename

When you deleted a directory and created a file with the same name, it
was treated like a directory, with ranger trying to preview it and
throwing lots of errors.  This was because it tried to look for the path
of the currently selected file in fm.directories - a directory cache -
and if a file with the same name existed as a directory once, it would
have found it there.
ext.widestring: Fix corner case (bug #32687)

https://savannah.nongnu.org/bugs/index.php?32687