Renamed SecurityGroupManager to FilterManager
Merge branch 'master' into refactor-security-groups

Conflicts:
	vnet/lib/vnet/openflow/dp_info.rb
Refactored filter manager and filters so they use events and the items hash. Interfaces no longer need to be aware of filters
Refactored connection manager to use events. Interfaces don't need to be aware of their connections any more.
Fixed a couple of fatal bugs that happened when removing interfaces
Added the filter classes that I forgot to push before
Changed the CONTRACK cookie to CONNECTION
Changed SECURITY_GROUP cookie to FILTER
Moved filter cookies to the Filters::Base class and removed the SG prefix
Merge branch 'master' into refactor-security-groups
Decided to have the filters return flows in arrays rather than having add_flows accept non-array arguments as well
Updated interface spec to expect the RELEASED_MAC_ADDRESS event on deletion
Took care of some #TODO comments in the filter manager
Removed the exclusion of non-vif interfaces from security groups. The latest refactors made it necessary for security groups to be implemented for everything
Re-enabled security groups for vif- and simulated interfaces
Merge branch 'master' into refactor-security-groups
Merge pull request #163 from axsh/refactor-security-groups

Refactor security groups