[2.4][Transit] Backport elm_transit_go_in() API (delayed start)

[2.4][Transit] Backport elm_transit_go_in() API (delayed start)

Author: Jee-Yong Um <jc9.um@samsung.com>
Date:   Tue Feb 17 08:34:46 2015 +0900

    elm_transit: Add elm_transit_go_in() API

    Summary:
    elm_transit_go() is executed immediately after it is called.
    elm_transit_go_in() starts transit in given seconds.

    @feature

    Reviewers: Hermet, seoz

    Reviewed By: seoz

    Subscribers: seoz, Hermet

    Differential Revision: https://phab.enlightenment.org/D1954

Change-Id: Ie6e9fc764f4685ae35ca6400dcc7b03f70feba29
Signed-off-by: Jee-Yong Um <jc9.um@samsung.com>