NetworkVxlanPortRangeError should base NeutronException

[yong sheng gong]

according to its usage, the NetworkVxlanPortRangeError should base NeutronException.

The usage:
raise exceptions.NetworkVxlanPortRangeError(vxlan_range=port)

the current NetworkVxlanPortRangeError:
class NetworkVxlanPortRangeError(object):
    message = _("Invalid network VXLAN port range: '%(vxlan_range)s'")

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/52955

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/52955
Committed: http://github.com/openstack/neutron/commit/cf3af07cfd9a2c6ba73b74ad1ef724182fcb339c
Submitter: Jenkins
Branch: master

commit cf3af07cfd9a2c6ba73b74ad1ef724182fcb339c
Author: Yong Sheng Gong <email address hidden>
Date: Mon Oct 21 23:34:53 2013 +0800

    change NetworkVxlanPortRangeError to base NeutronException

    Closes-Bug #1242756

    Change-Id: I902fa12795cda5ca70defaeb3b6959e3a0824565