Add networks attribute to RunServer params

Add networks attribute to RunServer params

This enables the starting of a server on a specific
network, which is required for some situations where
multiple networks exist.

This is not well tested at present, to do a proper job some
more network related operations need to be added so the
tests can do real operations.

https://code.launchpad.net/~gz/goose/run_server_networks/+merge/203113

(do not edit description out of merge proposal)

[gz, 2014-01-24 16:41:10]

Please take a look.

[natefinch, 2014-01-24 16:49:04]

LGTM

[dimitern, 2014-01-27 01:02:57]

In the future, please make sure you've updated the dependencies.tsv file when
making changes that need newer revisions of external libraries like goose.

[gz, 2014-01-27 07:31:56]

On 2014/01/27 01:02:57, dimitern wrote:
> In the future, please make sure you've updated the dependencies.tsv file when
> making changes that need newer revisions of external libraries like goose.

The juju-core change that requires this does include a dep bump to r116.