* eval() was previously used to marshall unchecked strings as
filter parameters for QuantumDbPluginV2.get_ports() via
the --fixed_ips flag.
* This change removes the use of eval and cleans up the filtering
implementation for get_ports().
* The new filtering implementation does not support arbitrary
OR'ing or AND'ing. Instead, multiple values for a given filter
key are logically OR'ed, and filters across keys are AND'ed.
* Example usage - filter for .2 or .3 in the given subnet:
quantum port-list -- --fixed_ips ip_address=10.0.0.3 \
ip_address=10.0.0.2 subnet_id=nOtaRealId
* Addresses bug 1052179
Change-Id: I451f33ae53e623f86015b3fc2e6a7ca2f51ee836