elm.hoversel: highlight selected item when auto update is enabled

elm.hoversel: highlight selected item when auto update is enabled

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    elm.hoversel: highlight selected item when auto update is enabled

    Summary:
    When auto update is enabled, the label of the hoversel will be that of selected
    item. This feature is usually used when changing state of something.
    Highlighting item previous selected will show what is current state more
    explicitly especailly hoversel has many items.

    Test Plan: elementary_test -to hoversel

    Reviewers: cedric, jpeg

    Differential Revision: https://phab.enlightenment.org/D4799

    Signed-off-by: Cedric BAIL <cedric@osg.samsung.com
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Signed-Off-By: Jeeyong Um <jc9.um@samsung.com>
Change-Id: Id38c8d2ae0a4ae4816306f1608ab7fc0f342fe0f