Added InterfacePortManager.
Removed old code from host port.
Removed port manager's dependency on interface manager.
Removed owner datapath from interfaces.
Fixes to specs.
Merge remote branch 'origin/master' into feature-owner-datapath

Conflicts:
	vnet/lib/vnet/core/interface_manager.rb
Fixed specs to work with new interface ports.
Added timing issue test to spec.
Removed test timer.
Fixed a bug in event tasks.
Changed how port_name/number in interface_manager and active_interface_manager.
Cleaned up interface manager.
Fixed loading of interfaces with port numbers.
Cleaned up interface port manager.
Added restrictions to what interface ports can be loaded by a datapath.
Properly set 'singular' when creating interface ports.
Do loading of simulated on network from interface port manager.
Replaced item_by_params with internal_retrieve.
Added mutex locks to MockDpInfo to ensure added/deleted flows in specs are thread safe.
Removed obsolete flow-related methods from MockDatapath.