Added network inclusion/exclusion to acquireNode

Added network inclusion/exclusion to acquireNode

I added Networks structure as a parameter of acquireNode
in maas provider. Its two members IncludedNetworks and
ExcludedNetworks get converted, in a similar fashion than
constraints, into url encoded parameters, according to 
~maas-maintainers/maas/trunk/view/head:/docs/networks.rst
they become, respectively "networks" and "not_networks"
For this I create an analog to convertConstraints which
I called convertNetworks, mostly to keep the two 
conceptually separated.
I added testing for the four variants I could think of
the structure values that where representative.
I also made a small cosmetic change to the converConstraints
test since it was very hard to read and I needed to based my 
own test on it

https://code.launchpad.net/~hduran-8/juju-core/add_networks_to_maas_acquireNode/+merge/211748

Requires: https://code.launchpad.net/~gz/juju-core/add_startinstance_params/+merge/211588

(do not edit description out of merge proposal)

[hduran, 2014-03-19 15:09:13]

Please take a look.

[natefinch, 2014-03-19 15:32:34]

On 2014/03/19 15:09:13, hduran wrote:
> Please take a look.

LGTM with one slight change.

[natefinch, 2014-03-19 15:33:52]

Doh, forgot to do the publish and mail thing.  Here's the change I mentioned
before.

https://codereview.appspot.com/77850043/diff/1/provider/maas/environ.go
File provider/maas/environ.go (right):

https://codereview.appspot.com/77850043/diff/1/provider/maas/environ.go#newco...
provider/maas/environ.go:172: func convertNetworks(params *url.Values, nets
environs.Networks) {
I'd rename this to be addNetworks, since it's adding on to the url.Values that
you pass in.

Also, don't actually need to make it a pointer, since url.Values is actually
just a map, and internally, maps are pointers to data structures, so you can
pass them like they're already a pointer.

[hduran, 2014-03-19 15:48:15]

Please take a look.

https://codereview.appspot.com/77850043/diff/1/provider/maas/environ.go
File provider/maas/environ.go (right):

https://codereview.appspot.com/77850043/diff/1/provider/maas/environ.go#newco...
provider/maas/environ.go:172: func convertNetworks(params *url.Values, nets
environs.Networks) {
On 2014/03/19 15:33:52, nate.finch wrote:
> I'd rename this to be addNetworks, since it's adding on to the url.Values that
> you pass in.
> 
> Also, don't actually need to make it a pointer, since url.Values is actually
> just a map, and internally, maps are pointers to data structures, so you can
> pass them like they're already a pointer.

Done.

[hduran, 2014-03-19 15:48:44]

I did change the name, it makes more sense now.
Also I changed params to be just passed as value.
Thank you.

[rvb, 2014-03-19 15:51:32]

https://codereview.appspot.com/77850043/diff/1/provider/maas/environ.go
File provider/maas/environ.go (right):

https://codereview.appspot.com/77850043/diff/1/provider/maas/environ.go#newco...
provider/maas/environ.go:175: //XXX Is this suposed to be a comma separated
list?
No, MAAs doesn't expect a comma-separated list, it wants a multi-valued URL
parameter.

As in http://server/?networks=net1&networks=net2
i.e.
v := url.Values{}
v.Add("networks", "<network1>")
v.Add("networks", "<network2>")

[hduran, 2014-03-19 16:10:31]

Please take a look.

https://codereview.appspot.com/77850043/diff/1/provider/maas/environ.go
File provider/maas/environ.go (right):

https://codereview.appspot.com/77850043/diff/1/provider/maas/environ.go#newco...
provider/maas/environ.go:175: //XXX Is this suposed to be a comma separated
list?
On 2014/03/19 15:51:33, rvb wrote:
> No, MAAs doesn't expect a comma-separated list, it wants a multi-valued URL
> parameter.
> 
> As in http://server/?networks=net1&networks=net2
> i.e.
> v := url.Values{}
> v.Add("networks", "<network1>")
> v.Add("networks", "<network2>")

Done.

https://codereview.appspot.com/77850043/diff/1/provider/maas/environ.go#newco...
provider/maas/environ.go:175: //XXX Is this suposed to be a comma separated
list?
On 2014/03/19 15:51:33, rvb wrote:
> No, MAAs doesn't expect a comma-separated list, it wants a multi-valued URL
> parameter.
> 
> As in http://server/?networks=net1&networks=net2
> i.e.
> v := url.Values{}
> v.Add("networks", "<network1>")
> v.Add("networks", "<network2>")

Done.

[rvb, 2014-03-19 16:41:26]

[...]
> Done.

Thanks for the changes.

LGTM.

[natefinch, 2014-03-19 18:47:25]

LGTM