[FIX] sap.m.Bar - visible false resulted in errors

- removed the resize listener if the bar was nor rendered
- improved router documentation

Change-Id: I135f64b2242747c1c68fc88220bb7e1dbbd04682
CSS: 0120031469 0000768225 2014
Merge "[FIX] sap.m.Bar - visible false resulted in errors"