elementary config: support lazy mount of user data area

elementary config: support lazy mount of user data area

It includes the following patches about supporting lazy mounting.

1.
    elm_config: Add fallback path to support lazy mount

    elm_config would access to user home directory to save their
    config information. However, elm_config couldn't accesss to
    the path because user data area could not be mounted
    (Lazy mount of user data area[below /opt/usr/] is applied)

    elm_config monitors some file which is created after mounting
    then if it doesn't exist, elm_config will access to the other path

2.
    config: update config data for processes which are launched before lazy mounting

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