chore(tooltips): not aligned in demo

[kellerapps]

http://valor-software.com/ng2-bootstrap/#getting-started
The tooltips are not aligned w/ their elements.

The tooltip on Datepicker demo doesn't appear.

[valorkin]

Problem is bigger than you think, modals\popups\tooltips are pain in the code in ng2 as for now
I need to properly export position service and reuse it across all elements

[valorkin]

implemented tooltips demo now aligned

[sqwk]

Possibly related: the v4 bootstrap tooltips are missing their arrows.

[valorkin]

interesting things about arrows in bs4
they are missing in bs4 off documentation
tooltip container has all this new classes
and in bs4 tooltip can be attached only to document.body
tooltip bs-tether-element bs-tether-abutted bs-tether-abutted-top bs-tether-element-attached-bottom bs-tether-element-attached-center bs-tether-target-attached-top bs-tether-target-attached-center fade bs-tether-enabled in

[sqwk]

Does this mean that tether.min.js needs to be included alongside ng-bootstrap as per the v4 documentation?

[valorkin]

not sure to be honest, I see where it is came from
https://github.com/twbs/bootstrap/blob/v4-dev/js/src/tooltip.js#L36

right now I am fixing system.js bundles, I will get to this a bit later