provider/local: Destroy partial environments

provider/local: Destroy partial environments

Destroy is improved so that it does not assume
a complete/working environment. It will now
handle the scenario where bootstrap failed to
gain sudo rights. It will also remove the
~/.juju/local directory as a final step.

Additionally, fixed Destroy to stop passing all
of os.Args through to the sudo call, and construct
the call explicitly.

Fixes lp:1273295
Fixes lp:1281863

https://code.launchpad.net/~axwalk/juju-core/lp1273295-local-destroy-broken-env/+merge/208748

(do not edit description out of merge proposal)

[axw, 2014-02-28 09:02:33]

Please take a look.

[axw, 2014-02-28 09:17:40]

Please take a look.

[axw, 2014-03-04 02:49:05]

https://codereview.appspot.com/67870045/diff/20001/provider/local/environ.go
File provider/local/environ.go (right):

https://codereview.appspot.com/67870045/diff/20001/provider/local/environ.go#...
provider/local/environ.go:168: fmt.Sprintf("chown syslog:adm %s", mcfg.LogDir),
Reviewers: this was slipped in as a drive-by fix for something I broke in my
rsyslog series. It's very difficult to test this in a meaningful way.

[thumper, 2014-03-04 03:00:03]

LGTM