Neutron network delete fails with brocade plugin

(Cherry picked from master + resolved conflicts)

Fixes bug: 1223747

Change-Id: I4a8235d4dcb0c14477835afafd0b5459ce6b01f6
Multiple Neutron operations using script fails on Brocade Plugin

Fixes bug: 1223754

Change-Id: I5c0f99d5261f6a3c1e86fc77536c1237cc7815b7
Merge "Neutron network delete fails with brocade plugin" into stable/grizzly
tmp

grep -nR zyluo.\\+dhcp_init * | awk '{print $5 $0}' | sort

Change-Id: Iedf1f5804e07639259c7689ea33fb305f0fa2a52