Minor cleanup of network manager and items.
Fixed spec after changes to network item base.
Moved vnet-specific db lookup from network manager to vnet edge handler.
Made generic modules for updating the state of items or properties.
Shortened the method name for adding state updates to queue.
Added a default install_item method.
Added ItemDpUuidMode for uuid items with mode property.
Added default unload_item method to manager.
Cleaned up interface manager updated to use new manager methods.
Update service manager with new manager methods.
Cleaned up route manager to use the new manager methods.
Fixed 'network_id_by_mac' call to use self instead of network manager.
Moved manager modules from 'openflow/event_helper.rb' to 'vnet/manager_module.rb'.
Add default values
Merge branch 'master' into db-table-refactoring
Merge remote branch 'origin/master' into refactor-other-managers
Updated security-group post to work with sinatra-browse
Merge pull request #202 from axsh/db-table-refactoring

Db table refactoring
Organised the many vnet api helper methods in modules
Changed the sinatra code blocks back to multiline. The unit tests fail otherwise.