Update to scijava-common 1.5.0

Changes include:

* The pom-scijava version was bumped to 1.52, which is pinned to
  scijava-common version 1.5.0.

* The PTService class hierarchy moved upstream to SciJava Common, so
  those classes have been removed from ImageJ, and package names changed
  in the import statements.

* The org.scijava.service.Service interface gained another method,
  registerEventHandlers(), which is normally taken care of by
  AbstractService, but we have a couple of direct implementors.
  So this commit adds method implementation stubs for those.