Adapt philips hue importer for appsgate support

Use event admin to send message notifing important operations done by the importer/discovery, like: authentication, error, updates
Update philips hue importer test

update test for the new version of the importer
Update philips gogo command

User injected bridge and light as optional, in order to display the command even if bridges do not exist
Fix ServiceReference null issue

Implementing scheme (elaborated by morgan) to overcome issue with null ServiceReference