Reduce Debug level logging

Change log level to trace for some of the trivial log messages

Change-Id: Ic6362612bc1f387023fffe9862997f65a2d18f05
Reviewed-on: http://review.couchbase.org/43829
Reviewed-by: Pratap Chakravarthy <prataprc@couchbase.com>
Reviewed-by: Deepkaran Salooja <deepkaran.couchbase@gmail.com>
Tested-by: Deepkaran Salooja <deepkaran.couchbase@gmail.com>