Starrating no pointermove

Use` pointerover` rather than `pointermove` and `pointerenter`.
It's less code, more efficient, and unaffected by ibm-js/dpointer#21.

@sbrunot, you said that it didn't work on iOS but I tried it and it works fine for me.  @seb-pereira also confirmed that it's supposed to work.  Maybe you got confused between `pointerenter` and `pointerover`.

Also includes some test fixes, in particular making the tests use proper promise chains, as required by Intern 2 and our coding standards.