Enabling OVS based Openstack Karaf Feature.

1) Feature Tests Pass:
https://jenkins.opendaylight.org/ovsdb/job/ovsdb-merge/259/org.opendaylight.ovsdb$features-ovsdb/testReport/

2) Features Comply with Guidelines: Yes (features starts with odl-, with description & no Start-levels)
https://git.opendaylight.org/gerrit/gitweb?p=ovsdb.git;a=blob;f=features/ovsdb/src/main/resources/features.xml;h=1a60f8d9dac857b81ca97f8010debd5e78a9da0e;hb=635dd9959632d1e59aaa54df4d8d95d4d8645ba4

3) Features Tested: Features have been tested for functionality with
	feature:install odl-ovsdb-openstack

4) Integration Test Impact : This brings in openstack support provided in OVSDB. If there are existing openstack tests, it is good to run it through them.

Signed-off-by: Madhu Venugopal <mavenugo@gmail.com>