logging integration

Change-Id: Iacfd08fe4b081a7487b02b81bf40b260128cfe18

change default log level

Change-Id: Ib667dd0d442fef2ccf6848552b59a5390c8c7113

add locking

Change-Id: I106aee8a2a104b881fc6d305374af0a4d7b1c301
Reviewed-on: http://review.couchbase.org/44603
Reviewed-by: Xiaomei Zhang <xiaomeizhangatwork@gmail.com>
Tested-by: Yu Sui <ysui68@gmail.com>
Revert "logging integration"

This reverts commit 95f6ab4143f27a5577f40b63d39b452ef2b6df68.

Change-Id: I309790667f2ed40f89cab263a3d3088d9fd72ce8
Reviewed-on: http://review.couchbase.org/44626
Reviewed-by: Yu Sui <ysui68@gmail.com>
Tested-by: Yu Sui <ysui68@gmail.com>