add geo tag scheduler filter

- cinder create 1 --metadata geo_tags={'country':'ar'}    currently not used..

- If not a new devstack, add to cinder/cinder.egg-info/entry_points.txt

[cinder.scheduler.filters]
CapabilitiesFilter = cinder.openstack.common.scheduler.filters.capabilities_filter:CapabilitiesFilter
RetryFilter = cinder.openstack.common.scheduler.filters.ignore_attempted_hosts_filter:IgnoreAttemptedHostsFilter
CapacityFilter = cinder.scheduler.filters.capacity_filter:CapacityFilter
JsonFilter = cinder.openstack.common.scheduler.filters.json_filter:JsonFilter
AvailabilityZoneFilter = cinder.openstack.common.scheduler.filters.availability_zone_filter:AvailabilityZoneFilter
GeoTagsFilter = cinder.scheduler.filters.geo_tags_filter:GeoTagsFilter

Note the GeoTagsFilter.