Doc: Setting navigation bar variables in qdocconf file.

-for navigation in offline mode.

Change-Id: I0f5b2c9fa466be4ce9885822ae57b93e453e8b01
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Docs: fix "missing \qmlpropertygroup" warnings

Change-Id: I73eab1f97e43726e7092d91c7898b8f628f19808
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@digia.com>