Add db8.conf.in upstart script

:Release Notes:
Add backward compatible upstart script.

:Detailed Notes:
DB8 server one database per process. Each database
have it own configuration and upstart script.
Some services have hardcoded dependency from db8 upstart
script and obviously start/stop it. To avoid broken
upstart logic, add db8.conf upstart script and dependency from
it

:Testing Performed:
Compiled and tested localy.

:QA Notes:

:Issues Addressed:
[ANG-298] Add conf files and upstart scripts for main/temp/mediadb

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

Change-Id: I3853b93017ebe210dbb439d9bf3f81ec3e026427
Reviewed-on: https://g2g.palm.com/4484
Reviewed-by: DCO Verification
Tested-by: Maksym Sditanov <maxim.sditanov@lge.com>
Reviewed-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Reviewed-by: Maksym Sditanov <maxim.sditanov@lge.com>