Firefly: Version 2 - major polish and browser support 

Here's the second version of the sheet.

Checkout the [Live interactive demo ](https://ramblurr.github.io/roll20-character-sheets/)

After a 4 hour playtest yesterday with my players I found a bunch of bugs and came up with many improvements.

The most notable is cross-browser support, functioning dynamic dropdowns without `<select>` tags.