Introduce Application class

Application class was born, RuntimeRegistry and ApplicationProcessManager are killed.

The newly added Application class is representing a "running application" accordingly to design described at https://docs.google.com/a/intel.com/document/d/1N0VVlut7JCWFbAEwTQc0loN9_D2JlOXRJprQeCbXY2U/ .

The in-browser tests were modified accordingly.