improve the router create form

[Masco]

router create a form is not complete.
it is missing the below items,
optional admin state and external network parameters
help text

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/155231

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/155231
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=55f85114ceb7e39b7227eaef7ff51bfab3c3b955
Submitter: Jenkins
Branch: master

commit 55f85114ceb7e39b7227eaef7ff51bfab3c3b955
Author: Masco Kaliyamoorthy <email address hidden>
Date: Thu Feb 12 15:22:23 2015 +0530

    improved the create router form

    In create router form some optional
    parameters and help text is missing.

    This patch is adding the admin state
    and external network parameters and
    help text.

    Change-Id: I36295a70f25f7e09a89d78aff07643e89c52ba2f
    Closes-Bug: #1421128