Make Neutron L3/DHCP agents OCF script more tolerant to mysql and keystone temporary fails.

In this implementation cleanup-script does not get information from Neutron API.
Script inspects network namespaces on this node for given agent type and removes
found ports from integration bridge.

Closes-bug: #1287716
Partial-bug: #1285929
Change-Id: I2dfb31f240dca652341c4623f237f6a143414448
Merge "Make Neutron L3/DHCP agents OCF script more tolerant to mysql and keystone temporary fails." into stable/4.1