edje - delete obj - null out freed items in structs/data

edje - delete obj - null out freed items in structs/data

Summary: This patch is from upstream.

commit c2e26a51215d379a6926b0ca44f3d4d664d84bb4
Author: Carsten Haitzler (Rasterman) <raster@rasterman.com>
Date:   Wed Apr 13 19:59:00 2016 +0900

    edje - delete obj - null out freed items in structs/data

    i just got a segv freeing ian invalid ptr... it SEEMS as if something
    has tried to free and edje object twice... but i can't be sure as
    valgrind can't catch this. it's a one-off, so ensure after free, we
    NULL out things we freed to avoid this.

    @fix

Change-Id: I201d34850e3cf5f3981236065f04abb197aebbaa
Signed-off-by: Prateek Thakur <prateek.th@samsung.com>