Drop root permission when launching apps in command line

Drop root permission when launching apps in command line

- Launching apps in command line is useful to investigate issue with printf or other tools.

[Issue#]   N/A
[Problem]  Indicator does not show correctly when launched via command line.
[Cause]    Caused by various reasons - e.g., DAC and SMACK.
           * When applications are run with "root" permission,
             some of the platform feature (DAC, SMACK, etc) will fail to initialize.
           * Indicator issue is one of the issues which will occurr
             when web application is running on the "root" permission.
[Solution] Drop root permission
           * To support normal operations when launched by command line,
             web app needs to drop "root" permission before doing something.

[Remarks] Implementation details
    * Drop "root" permission should be done before touching  platform resource.
    * Current implementation point is too early, before attaching database, to access widget dao.
    * To resolve this, using ail to get various information to use privilege API.

Change-Id: I4c3014277da924cff590a80cb01c411655418a05