elm: atspi - bring HIGHLIGHT related changes

elm: atspi - bring HIGHLIGHT related changes

1. atspi: implement HighlightGrab and HighlightClear methods
  - commit 29e253e2f7ef3c632ac3a64c489bf569df407f30
  - Author: Lukasz Stanislawski <l.stanislaws@samsung.com>
  - Date:   Wed Dec 9 15:19:29 2015 +0100

2. win: add accessibility highlight.
  - commit d4753268ad02d0c25c16f815003c70b158879ca7
  - Author: Lukasz Stanislawski <l.stanislaws@samsung.com>
  - Date:   Wed Dec 9 10:03:31 2015 +0100
  - Accessibility highlight allows to visually marked given Evas_Object
    on elementary window. Its main purpose is to attract user attention
    to given object without triggering any widget events focus changes etc.
    Accessibility highlight is pararell concept to focus higlight.

@tizen_feature

Change-Id: I647feaf83dd1ad80a4586e6bf20f3792bd5203a1