Remove obsolete examples

These examples were more like manual tests than examples. These
features are now covered and documented in the music player example.
Furthermore, corresponding manual test applications already exist.

Change-Id: I28d857cd704e08a8ef5e6763d6403885119accba
Reviewed-by: Ivan Vizir <define-true-false@yandex.com>
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>