Rework swift, neutron and glance configs discovery feature.

For now it's only nova, keystone, glance, cinder, mysql and rabbitmq services configuration files are discovering due to validation process. It's very important to add swift, neutron and glance processes config discovering, because we already have some config-schemas for that services(not for all configs).
For example, neutron processes each has its own config:
neutron-dhcp-agent --config-file /etc/neutron/neutron.conf --config-file=/etc/neutron/dhcp_agent.ini
neutron-openvswitch-agent --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/plugins/ml2/ml2_conf.ini
neutron-l3-agent --config-file /etc/neutron/neutron.conf --config-file=/etc/neutron/l3_agent.ini
neutron-metadata-agent --config-file /etc/neutron/neutron.conf --config-file=/etc/neutron/metadata_agent.ini
neutron-server --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/plugins/ml2/ml2_conf.ini
Swift has:
swift-container-server /etc/swift/container-server/1.conf -v
swift-account-server /etc/swift/account-server/1.conf -v
swift-object-server /etc/swift/object-server/1.conf -v
swift-proxy-server /etc/swift/proxy-server.conf -v
Glance:
glance-registry --config-file=/etc/glance/glance-registry.conf
glance-api --config-file=/etc/glance/glance-api.conf