Simplify vCard implementation.

- make ImportProcessor/ExportProcessor implement both Runnable and
  Future (as FutureRunnable, introduced in 1.6). Getter capability
  for Future interface is disabled.
- use just one hash map instead of managing three different ones.
  Now that both processors are also Future<Object>, it is much
  easier to do so.

Change-Id: Ia9deba6f4063eaae48d42a295d2ce84aca0a424f
4 files changed