ICONS: Exchanged icons between tango and human and small change to zoom mode

Change-Id: Iab3f148258204fefc667e94307adfa0537364ac9
Reviewed-on: https://gerrit.libreoffice.org/12125
Reviewed-by: Matthew Francis <mjay.francis@gmail.com>
Tested-by: Matthew Francis <mjay.francis@gmail.com>