terminateAndRecover function for Actor

[simerplaha]

Recovery in Actors is invoked only when messages are being send to a terminated actor or if processing a messages throws an Exception. Recovery is not invoked on queued/unprocessed messages after termination.

A terminateAndRecover function is needed which would apply recovery function to all queued/unprocessed messages. This function is needed for deleting memory-mapped files on Windows (see #156) specifically when invoking db.delete() and db.close().