scheduler host_manager needs service for filters
scheduler host_manager needs service for filters

distributed scheduler isn't checking service_is_up or
services['disabled'] due to filters not having access to service.

Fixed both.  Since ec2 API also uses service_down_time, I moved
service_is_up() into utils and made ec2 use it.

Change-Id: I0321844a47031b2de4d8738e032a4634edd1e945

openstack/oslo.versionedobjects,citrix-openstack-build/oslo.versionedobjects