VMware NSX: Fix db integrity error on dhcp port operations

If the dhcp port and network disappear, ensure that
the integrity constraint violation that results from
inserting the neutron/nsx port mapping to the DB does
not propagate the exception all the way through, but
instead is caught and handled correctly.

Closes-bug: #1265472

Change-Id: I3ae072729d579def0bd9658241eda1011a3dcfa0
L3 Agent can handle many external networks

With this patch a l3 agent can handle
any networks by setting the neutron
parameter external_network_bridge
and gateway_external_network_id to
empty.

Related-Bug: #1234750
Related-Bug: #1194350

Change-Id: Id260a239df23951da730513f40cda490002effc3
Make timeout for ovs-vsctl configurable

This patch adds a new configuration variable for the timeout on
ovs-vsctl commands, and sets the default timeout to 10 seconds.
This is aimed at allowing users to tune the agents in order to avoid
timeout errors on their deployments.

Change-Id: I73ea0d0de49a4b4a118bc2d68ad9c093ea122717
Closes-Bug: #1254520
Imported Translations from Transifex

Change-Id: Ic9f6e6754db748acf456cc69b38c4268b86fe3e1
Merge "VMware NSX: Fix db integrity error on dhcp port operations"
Merge "Make timeout for ovs-vsctl configurable"
Merge "L3 Agent can handle many external networks"
Fix pip install failure due to missing nvp.ini file

It looks like sdist does not support symlinks, therefore
letting nvp.ini point to nsx.ini is not a good solution.
Since nvp.ini is going away, leave a copy for now, but
add a warning so that users are aware of the switch,
whilst preserving full backward-compatibility.

Closes-bug: #1266555

Change-Id: Id98c41145712583072a8e63a5de31ecc1074e420
tmp

Change-Id: Iecd3a2cbd8af2a2fc6a09b009fbf8226881e3815