os-networks extension

This commit adds the os-networks extention. This can be used to view
details about the nova-network-based networks that a tenant has access
to.
diff --git a/openstack/compute/v2/extensions/networks/requests.go b/openstack/compute/v2/extensions/networks/requests.go
new file mode 100644
index 0000000..eb20387
--- /dev/null
+++ b/openstack/compute/v2/extensions/networks/requests.go
@@ -0,0 +1,22 @@
+package networks
+
+import (
+	"github.com/rackspace/gophercloud"
+	"github.com/rackspace/gophercloud/pagination"
+)
+
+// List returns a Pager that allows you to iterate over a collection of Network.
+func List(client *gophercloud.ServiceClient) pagination.Pager {
+	url := listURL(client)
+	createPage := func(r pagination.PageResult) pagination.Page {
+		return NetworkPage{pagination.SinglePageBase(r)}
+	}
+	return pagination.NewPager(client, url, createPage)
+}
+
+// Get returns data about a previously created Network.
+func Get(client *gophercloud.ServiceClient, id string) GetResult {
+	var res GetResult
+	_, res.Err = client.Get(getURL(client, id), &res.Body, nil)
+	return res
+}