ui-router-ng2: uiSref generates `null` href

[christopherthielen]

See: https://plnkr.co/edit/oQ6b0dFzrHLfepGLddV1?p=preview

I think this might be caused by the UISref being used outside a UIView

[christopherthielen]

See #2909

[christopherthielen]

See also #2913, following href, not using click handler. possibly a different bug?

[christopherthielen]

See a151f71#commitcomment-18635931 for a potential explanation: Root component is bootstrapped and the uiSref's href is created before the states exist.

[christopherthielen]

As discussed in a151f71, this is caused by the root component bootstrapping before the states are registered. A workaround is to bootstrap a UIView instead of a custom component:

https://plnkr.co/edit/LX0LuckSvPJHPNUq9gYJ?p=preview

[christopherthielen]

Should be fixed by 874fc07