Manta

- `mantash du ...`

- `mantash rm PATH ...` now supports globs.
- Allow the second arg to `mantash ln` to be optional a la typical `/bin/ln`.
- Fix usage of `\n` in `MANTASH_PS1` envvar.

- [MANTA-2530] Add `MantaClient.{get_job,get_job_input,get_job_output,
get_job_failures,get_job_errors}` wrappers of the `RawMantaClient` to
handle retrieving [*archived job
results*](https://apidocs.joyent.com/manta/jobs-reference.htmljob-completion-and-archival).
- Change `mantash jobs` to emit a flat list of job IDs by default
(like `mantash ls`). Use `-j|--json` to get a JSON list.
- Add `-v` option to all the examples for easier verbose output.
- [issue 23] `cd foo/bar` where no "foo" dir exists crashes mantash
- Add 'vim' alias to 'vi' in mantash.

- [pull 14] Fix `fingerprint_from_ssh_pub_key()` parsing of SSH keys
which caused fingerprint calculation errors for *some* SSH keys with
comments. (Thanks <https://github.com/tomahn>!)

- [issue 20] Change cache dirs used by `mantash` and the client to include
the effetive UID. This avoids permission issues if one runs as root,
e.g. via `sudo -E mantash ...`, once.

- [issue 19] Paramiko 1.14.0 changed `<Agent key>.sign_ssh_data()` signature
which broke request signing via the ssh-agent. Fix that.

- Add limited `mantash mv` command for moving Manta objects and dirs around.

- Fix test suite breakage.

- [issue 18] Add MANTA_NO_AUTH support for running python-manta in a Manta
job or mlogin session. For example, this means that you can now much more
easily use python-manta in a manta job by using `pip install manta` in
your init command. E.g. using the node-manta `mjob` command:

mfind /bob/stor/datafiles -to \
| mjob create --init 'pip install manta' \
-s /bob/stor/scripts/my-processor.py \
-m '/assets/bob/stor/scripts/my-processor.py'

Now "my-processor.py" can `import manta` to read and write to Manta inside the
job.

- [issue 16] A start at some encoding handling fixes in `mantash` for paths
with non-ascii characters.

- [issue 15] Fix tab completion in `mantash` to escape shell special
characters.

- 'mantash sign MANTA-PATH' wrapper around msign from the node-manta tools.

- 'mantash json' simple command to JSON-pretty-print a smallish JSON file.

- 'mantash head' and 'mantash tail' first cuts.

- Fix mantash bash completion to append '/' for directories (both for manta dirs
and local dirs as appropriate for the command).

- Add 'mantash login ...' command. This calls out to the awesome
[`mlogin`](https://apidocs.joyent.com/manta/mlogin.html) tool from the [Manta
Node.js SDK (aka node-manta)](https://github.com/joyent/node-manta), hence
this requires that you have node-manta setup and on your PATH.

- Sort 'mantash find ...' output.

- Add support to 'mantash' to remember user areas visited for future
tab completion. For example, if you are "bob" and you've visited
"/sue/public/..." then "cd /s<TAB>" will complete to "cd /sue/" for you.

- Packaging tweaks, improved README, clean rev for pypi.