Networks are not scheduled to DHCP agents for Cisco N1KV plugin

With the config option 'network_auto_schedule = False' in
neutron.conf, networks do not get scheduled to available DHCP
agents. The fix is to explicitly schedule the network as part
of the subnet creation flow.

Conflicts:
	neutron/tests/unit/cisco/n1kv/test_n1kv_plugin.py

Change-Id: Id1f94a5844111a916f984d6dd7bda2cb4e11e1ee
Closes-Bug: #1356609
(cherry picked from commit 0fcedae747f257e2424b669ec65f32b76f12155a)
update vsm credential correctly

Today if we modify the n1kv VSM credential in the cisco_plugins.ini, the
older VSM ip address remains in the db, and all requests are sent to
the older VSM. This patch deletes all n1kv VSM credentials on neutron
start up before adding the newer VSM credentials. Hence making sure
that there is only one n1kv VSM IP address and credential in the db.

Change-Id: I772a86bf896a1d3d9c69c545ce6918b0fe3a2e48
Closes-Bug: #1341014
(cherry picked from commit 487b98a73f6be41697dd4f59a245f1a7f338a72f)
Merge "Networks are not scheduled to DHCP agents for Cisco N1KV plugin" into stable/icehouse
Merge "update vsm credential correctly" into stable/icehouse