[3/4] Settings: switch to SuperSU from Chainfire

If SuperSU is installed, show an entry in Settings below
"Developer options", which launches SuperSU when tapped.
At boot time SuperSU will detect if com.android.settings
contains the resources from this patch, and if so it
will hide itself from the launcher. This was implemented
in v1.85, so we only show the entry if the installed
SuperSU version is at least that.

PS2: Better Drawables courtesy of Lo

NamelessRom modifications:
as we had koush superuser implemented before, we remove
essential parts of it, as we replace it with SuperSU.

though the header is kept and always removed, because we
are going to add a check later as well, if koush' su is
installed.

Signed-off-by: ayysir <dresadd09691@gmail.com>
Signed-off-by: houst0nn <houstonn@gmail.com>
Signed-off-by: Evisceration <eviscerationls@gmail.com>
Change-Id: I1796d92458587b9e961d5d8e6d58099e8367834d