Add support for local providers.

Add support for local providers.

Bootstrap the environment with "sudo" if
the environment is configured to use the 
local provider.

Also improved debugging documentation.

Tests: make check

To QA this, just run `.venv/bin/python juju-quickstart` 
as you are used to, but with the local provider: 
try to deploy a bundle, try to re-run quickstart again 
with the environment already bootstrapped. 
In general the application should ask for sudo password 
and then proceed as usual.

https://code.launchpad.net/~frankban/juju-quickstart/local-provider/+merge/195952

(do not edit description out of merge proposal)

[frankban, 2013-11-20 12:26:20]

Please take a look.

[rharding, 2013-11-20 13:57:12]

Code looks good, doing qa.

[rharding, 2013-11-20 14:24:24]

LGTM + qa ok in local

[frankban, 2013-11-20 14:51:28]

*** Submitted:

Add support for local providers.

Bootstrap the environment with "sudo" if
the environment is configured to use the 
local provider.

Also improved debugging documentation.

Tests: make check

To QA this, just run `.venv/bin/python juju-quickstart` 
as you are used to, but with the local provider: 
try to deploy a bundle, try to re-run quickstart again 
with the environment already bootstrapped. 
In general the application should ask for sudo password 
and then proceed as usual.

R=rharding
CC=
https://codereview.appspot.com/29540044

[frankban, 2013-11-20 14:55:51]

Thank you!