Threading issues

[rymsha]

• Some OSGi services create executors (or other threads) which are never shut down. This leaks threads when configuration of such services changes. Solution is to call shutdown/shutdownNow in deactivate methods.

• Some Executors are constructed with ThreadFactory which specifies UncoughtExceptionHandler, which is never called because all exceptions are actually caught by executor itself. Solution is to catch exceptions/throwables for correct processing directly inside Runnables.

• Similar but worse issue is in use of ScheduledExecutors as they stop repeating tasks in case of exceptions thrown inside tasks.
  Attempts to solve this were made, but they didn't account Errors which were silently swallowed.
  Solution is to catch all exceptions so repeating stays alive. And log Errors before rethrowing them.

• Some long-lived Threads have no names which makes them harder to identify. Give them appropriate names.

[rymsha]

for instance TaskManagerImplTest fails every now and when