* WIP: move to bytes codec
* Progress on adding collect helpers
* Progress on adding collect helpers
* Add in line splitting back to lines
* Lines outputting line primitives
* Close to ready?
* Finish fixing lines
* clippy fixes
* fmt fixes
* removed unused code
* Cleanup a few bits
* Cleanup a few bits
* Cleanup a few more bits
* Fix failing test with corrected test case
* Fix and refactor cd for Filesystem Shell.
Reorder check conditions, don't check existence twice.
If building for unix check exec bit on folder.
* Import PermissionsExt only on unix target.
* It seems that this is the correct way?
This improves incremental build time when working on what was previously
the root package. For example, previously all plugins would be rebuilt
with a change to `src/commands/classified/external.rs`, but now only
`nu-cli` will have to be rebuilt (and anything that depends on it).
