pending_close should be considered an idle state
pending_close should be considered an idle state

That allows other threads to bump the ref count for the object
and keep a reference to the object (not using ewb) and use the
on_disconnect listener to decrement the ref counter and tell
the shutdown to complete.

Change-Id: Ifd103ce6c3a83f25b0a94769dedc1f7b446da19b
Reviewed-on: http://review.couchbase.org/99291
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Daniel Owen <b3fc0e1a51f252986e60be7da121b74d3ac6845f@couchbase.com>

daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine