Small code rework

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>
Chandec core.content.menu to core.content.nav to be used as global
navigation service and added core.content.menu as menu factory.

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>
Added missing core.content.nav as menu to app construction

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>
Changed app contructor to use new settings structure

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>