Move status to nav bar, small CSS fix for navbar

* NavCtrl->MainCtrl, that's what it is
* introduce context in MainCtrl: now status and host are accessible to child scopes.
* moved status text to nav bar
* css for nav bar to match the content width

Signed-off-by: debuger <debuger@softwarefrontier.com>
Merge branch 'dev/dz' of https://github.com/dzimine/collectd3 into dev/dz