Fix deletion of STI temp dir on exit

Code cleanup/refactoring.

Change call from os.Remove to os.RemoveAll to remove the temp dir and
its contents.

Only chown /tmp/artifacts.

Remove the chgrp portion of the chown calls as it shouldn't be necessary
and it keeps the user running sti from being able to delete the temp
dir.

Change /tmp/artifacts from 755 to 775 so it's group writable, meaning it
should be able to be deleted by the host user.

Fix issue where the build would fail when trying to determine the
default scripts URL if the image didn't already exist locally.

Fixes #164
Merge pull request #176 from ncdc/sti-temp-dir3

Merged by openshift-bot
Make isolated containers respond to SIGTERM

Modify the container init template to execute `su` using /.container.cmd
as the "shell" and don't specify a command. This allows the actual RUN
command to receive signals (i.e. SIGTERM) so it can be stopped cleanly.
Revert "WIP geard - Support additional systemd slices"

This reverts commit 5939ebd85641ff0dff470bce9ed6bdfbad5d32ae.
Merge pull request #177 from smarterclayton/revert_slice

Revert "WIP geard - Support additional systemd slices"
Card online_node_472 - Support additional systemd slices
WIP geard - Support additional systemd slices

* Support validation over API
Merge pull request #179 from jwhonce/origin_node_472

Merged by openshift-bot
Demo updates - test plan & multihost workaround

Update the demo with JMeter setup instructions and work around a bug
with multi-host 'gear deploy'.
Merge pull request #180 from pmorie/demo-multi

Demo updates - test plan & multihost workaround
Card origin_node_472 - Provide default slice during validation
Merge pull request #181 from jwhonce/origin_node_472

Merged by openshift-bot
Allow geard to run STI built images

Modify geard so it bind mounts a directory for the container init and
cmd scripts, instead of bind mounting the individual files. This is
temporary and can be changed back to files once we have a build of
Docker with
https://github.com/dotcloud/docker/commit/d535d9810012b18ca83f86aa416ff4a08bb49804
in it.

Change STI to put the container init script in /.sti.init so it doesn't
conflict with geard's /.container.init directory (this is also temporary
and will be changed to file bind mounts for the same reason as stated
above)
Merge pull request #182 from ncdc/geard-container-init-as-dir

Merged by openshift-bot
Refactor the client API to remove core dependencies

* Move Job implementations to explicit classes
* Make daemon pluggable
* Other cleanup
* Add 'gear purge'
* Add -all to gear list-units (closes #173)
Merge pull request #178 from smarterclayton/refactor_client_api

Merged by openshift-bot
Add package docs and describe high-level patterns.
Merge pull request #183 from pmorie/docs

Merged by openshift-bot
Fix typo in STI readme
Merge pull request #185 from VojtechVitek/typo

Fix typo in STI readme
Update netlink package location in libcontainer