Count out unnecessary but error causing tests

Added those tests with nosetest 'exclude' option. '--config=setup.cfg'
is also required when run_test.sh.
Fix unittest errors and failures

1. Fix DuplicateOption error on dhcp_agent and security_groups_rpc
   with 'CONF.root_helper'
2. Fix metadata_agent test_report_state failure and removed not
   applicable test with Grizzly
Fix testcase 'test_create_subnet_with_two_host_routes' failed

Fix bug 1179348

Change-Id: I0cd5d303da0f394cec173aeee52efcd337282c94
Signed-off-by: Christoph Thiel <c.thiel@telekom.de>
Fix testcase 'TestPortsV2.test_range_allocation' failed randomly

Fix bug 1179370

Change-Id: Id5645546c98549c9d7cf68359e0f6fa128ad84b7
Signed-off-by: Christoph Thiel <c.thiel@telekom.de>
Skip test_db_plugin:test_no_more_port_exception

NG allows port creation with /32 subnet, so this test case will
not work as expected.
Remove port ID from dhcp device ID

Dhcp device ID originally includes port ID, but we removed it to
make dhcp listen & gateway IP the same at all cnodes to short
live migration time.
Add 'option:netmask,255.255.255.255' to dnsmasq opt

To give VM with /32 subnet IP, 'option:netmask,255.255.255.255' this
option was added to dnsmasq opt file.
Add metadata_network config option

metadata_network config added to provide isolated metadata network
when enable_namespaces=False, which is NG case.
Merge pull request #32 from hyunsun/UCLOUDNG-1397

UCLOUDNG-1397: make quantum unit test passed in python unittest
Return freed IP to the pool right after the release

Quantum waits for the freed IP to be expired (dhcp lease) to
return to the pool. This results in successive VIP move failure.
With this fix, freed IP will be available as soon as it is released
so that the VIP move can be done regardless of dhcp_lease_duration.