MB-100: KVShard + IOManager + few fixes

- 04/29/2013 1800 hrs

Change-Id: I0e5a691e99276f751e696f8c57259fc066f1b57c
Reviewed-on: http://review.couchbase.org/25954
Reviewed-by: abhinav dangeti <abhinav.dangeti@gmail.com>
Tested-by: abhinav dangeti <abhinav.dangeti@gmail.com>