* close all directory streams in case of IOErrors
* raise error on invalid input types in File operations
* properly catch eXDEV in moveFile instead of all errors
We shouldn't follow symlinks in our internal paths, because that makes
us lose information. However, we normalize where we could have passed
user input, so we don't end up with ill-formed anchors/names.
canonicalizePath tries to remove as many symlink components as possible,
but this is not what we want for a lot of operations like copying
files. So instead we preserve the last path component if it's a symlink
and canonicalize it's parent filepath.
we now have:
* AnchoredFile -- for representing a file with context
* File -- for representing a file only
Both representations mean "file" in the broader sense, including
directories.
