Deploy lazy-sync for sandwich db

:Release Notes:
Deploy lazy-sync for sandwich db which waive sync()

:Detailed Notes:
Lazy sync will be enabled if sandwich.sync is 2.
In this case, leveldb sync option is set to false, but every 1 second,
it do sync() for each opened leveldb in another thread.

:Testing Performed:
Checks whether test_db_performance shows better performance

:QA Notes:

:Issues Addressed:
[CMB-39] Proposal lazy sync for improving writing performance

Open-webOS-DCO-1.0-Signed-off-by: Junku Park <junku.park@lge.com>

Change-Id: Id703e3573d7b9003699e41918cc30d91f394c7f4
Reviewed-on: https://g2g.palm.com/6403
Reviewed-by: DCO Verification
Reviewed-by: Junku Park <junku.park@lge.com>
Tested-by: Junku Park <junku.park@lge.com>
Reviewed-by: Yongil Jang <yi.jang@lge.com>
Reviewed-by: Kyouhyun Hwang <kyouhyun.hwang@lge.com>
Reviewed-by: Maksym Sditanov <maxim.sditanov@lge.com>
Revert "Change transaction order"

:Release Notes:
This reverts commit 66f920d255cfc3fd3bd90f21644f20d6c3d26c45.

:Detailed Notes:
After switching to leveldb sandwitch this commit not required

:Testing Performed:
Compiled and tested localy.

:QA Notes:

:Issues Addressed:

Open-webOS-DCO-1.0-Signed-off-by: Maksym Sditanov <maxim.sditanov@lge.com>

Change-Id: I7d8477d1f7f979b69f1f9c469d960183c7144c3a
Reviewed-on: https://g2g.lgsvl.com/6475
Reviewed-by: DCO Verification
Tested-by: Maksym Sditanov <maxim.sditanov@lge.com>
Reviewed-by: Oleg Yablokov <oleg.yablokov@lge.com>
Reviewed-by: Maksym Sditanov <maxim.sditanov@lge.com>
Add batch unit test

:Release Notes:
Add testing of batch, when in batch we have put and merge operation

:Detailed Notes:
Test batch with put/merge of the same object

:Testing Performed:
Compiled and tested localy.

:QA Notes:

:Issues Addressed:
[BHV-13271] DB8 don't response for batch reques

Open-webOS-DCO-1.0-Signed-off-by: Maksym Sditanov <maxim.sditanov@lge.com>

Change-Id: I04613ab696283e46c4707b4534c4b7a44a7ec000
Reviewed-on: https://g2g.lgsvl.com/6476
Reviewed-by: DCO Verification
Tested-by: Maksym Sditanov <maxim.sditanov@lge.com>
Reviewed-by: Maksym Sditanov <maxim.sditanov@lge.com>
Merge branch 'develop'

Open-webOS-DCO-1.0-Signed-off-by: Oleg Yablokov <oleg.yablokov@lge.com>

Change-Id: Ide16715b872574e180e5a2ee22f54cdac6b697b8