* archive: relative links only
Ensure all links written into tarfiles generated from Spack prefixes do not contain symlinks pointing outside the prefix
* binary_distribution: limit extraction to prefix
Ensure files extracted from spackballs are not links pointing outside of the prefix
* Ensure rpaths are properly set on Windows
* hard error on extraction of absolute links
* refactor for non link-modifying approach
* Restore tarball extraction to original impl
* use custom readlink
* cleanup symlink module
* make lstrip
Modifications:
- [x] Move `spack.util.string` to `llnl.string`
- [x] Remove dependency of `llnl` on `spack.error`
- [x] Move path of `spack.util.path` to `llnl.path`
- [x] Move `spack.util.environment.get_host_*` to `spack.spec`
