Clarify message when no probes are cleared

Log number of probes which were deleted by
using neutron-debug probe-clear
Closes-Bug: #1333103

Change-Id: I5b53f0c4651c6df491d414d7d65f98c4a84a5987
L3 Metering label as shared

With this patch metering labels can be set
as shared so that the rules associated with
this label will be applied to all routers for
all tenants.

Also changed all attributes on metering labels
to not allow updates ('allow_put': False),
since there are no update methods.

Partially implements
blueprint l3-metering-mgnt-ext

DocImpact

Change-Id: Ice405585fc50786d52eecc35c01605ac0e9550ac
Remove the Cisco Nexus monolithic plugin

The Cisco Nexus monolithic plugin does not work without the Open
vSwitch plugin. The Open vSwitch plugin is scheduled to be removed
as per #1323729. This patch removes the Nexus Hardware switch
related plugin code. The N1KV virtual switch related code will
still remain in the tree as it doesn't depend on Open vSwitch
plugin.

Closes-Bug: #1350387
Change-Id: I2542e92c25e9280e975c3903afb9114e850a966a
Merge "Clarify message when no probes are cleared"
Merge "L3 Metering label as shared"
Merge "Remove the Cisco Nexus monolithic plugin"