update-port error if port does not exist in nvp

Previously the NVP plugin would query NVP for the quantum port id that was
stored in the port as a tag in NVP. Later, a look up table was added in order
to directly look up the ID without having to go to NVP. The problem that can
arise is that if a port was created in folsom before this lookup table was
added and then deleted from NVP directly an error will be raised when calling
update_port(). This patch fixes this potential problem.

Fixes bug 1172006

Conflicts:

	quantum/plugins/nicira/nicira_nvp_plugin/QuantumPlugin.py

Change-Id: I08c74e305449f7fe32897abf43ceb430c959b02d
(Cherry picked from 31946ebb5d7748fada269bd867f0e6d6e02ef736)
get_security_groups now creates default security group

If one called get_security_groups() previously the default security
group would not be created until the tenant created a network. This
exposed a bug when an admin creates a shared network and a tenant tried
to boot a vm on it without having any networks.

Fixes bug 1171997

Change-Id: I899203424c03353a1ee6567c9ddbaecd7dc25001
Merge "update-port error if port does not exist in nvp" into stable/grizzly
Merge "get_security_groups now creates default security group" into stable/grizzly