Update Waves to v0.7.5

[Queatz]

I was looking for a more performant solution for my Angular project besides calling Waves.displayEffect() each time a new component loads and saw that there is now Waves.init() which seems to be a one-time call.

https://github.com/fians/Waves/blob/master/src/js/waves.js

[DanielRuf]

We are currently using a modified waves.js version but we can probably add the init method and migrate the affected lines in Materialize.

[Dogfalo]

Why do you need to call displayEffect() multiple times? As long as the element has waves-effect it should still be able to trigger the waves effect without having to call displayEffect()