refactor(NgView): Make use of the ViewPort

This should be solving #704 however I can not get the test to work, any hint would be appreciated here (it seems to work fine in my test app).

Todo:
- [x] uniit the test, make sure all pass,
- [x] rewrite the commit msg (closes #704)

_There are a few style changes in the first commit, if this is still too much, let me know but it should be pretty  localized and trivial_