Control active number of REST calls from Cisco N1kv plugin to VSM

Add a config parameter to Cisco N1kv plugin to determine the total
number of active REST calls that can be made to the VSM.

Change-Id: I66433ef5673d35badcd3adc2defa43e578d4094f
Closes-Bug: #1329099
Removed local modification in incubator code

Now that 'rpc' module is removed from the tree, we're safe to restore
the original code here.

blueprint oslo-messaging

Change-Id: I10ee03a3e2b06cdc25bd071f3cefa06966c6ebf3
Imported Translations from Transifex

Change-Id: I77134cdd6b3a8177d94a1deac3646d5cd4abb20d
Merge "Imported Translations from Transifex"
Merge "Control active number of REST calls from Cisco N1kv plugin to VSM"
Merge "Removed local modification in incubator code"