Add option to ignore backend HTTP error in BigSwitch plugin

This patch fixes the way the BigSwitch plugin ignores 404
errors from the backend controller by allowing HTTP codes
to be selectively ignored on REST calls. This prevents
unnecessary exception handling and failover logic in calls
where 404 codes are acceptable.

Fixes: bug #1200023

(cherry picked from commit 5b4ef2a513bc7c8d2a2eecb57f656bf42bb0dd52)
Change-Id: Ia1118c039af3b45d96fb3f8a5fb5d3febdf50f4f
Clean up Cisco plugin config parameters

Change-Id: I3095f6aa0aa182592bd939ec59bac1820f15676f
Fixes: bug 1201537
Merge "Clean up Cisco plugin config parameters" into stable/grizzly
disable ns-metadata-proxy if we not using namespaces
FIX: destroy_metadata_proxy
ExtendedOVSInterfaceDriver template  + some debug
ExtendedOVSInterfaceDriver + insert in internal_network_added
handy revert -- This code must be not here.
attach ip address directly to br-ex.

And do not touch default routing if interface != br-ex
floating IP. first step.
using 'ip addr add ...' instead my custom  driver.add_l3 mix-in
log messages
log messages
reformat
remove dangerous import