Offers: full fat, lite, extras

Latest release (from 15 Dec;
https://github.com/zurb/foundation-sites/releases/tag/v6.3.0)

For #34

Resolves #58

Most notably adds jQuery v3 compatibility.

Allows it to inherit parent size or editor specified

Avoids bug #50 — also makes more efficient

Instead of creating and destroying we just show or hide.