Tango icon set changes

Change-Id: I1e36aeb5572e2e5fcce7283531bcba723e095214
Reviewed-on: https://gerrit.libreoffice.org/10493
Reviewed-by: Adolfo Jayme Barrientos <fitojb@ubuntu.com>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>