Scrolling is not working on Firefox

[icoloma]

Firefox will not scroll on body but on html: http://stackoverflow.com/questions/12222485/why-to-use-html-body-for-scrolltop-instead-of-just-html

With the current code examples it's impossible to know which one to use, and one has to correct that manually.

[marekhrabe]

In pseudo code, we could add something like this at the beginning of function

if element is document.body then animatedScrollTo(document.documentElement, samePosition, sameTime)

With that change we will be animating both properties at same time for compatibility and user of library will be still using just document.body to initialize animation (just like in the example)

[icoloma]

That means calling everything twice, including requestAnimationFrame. In my head, it makes more sense to also accept an array of values and in that case iterate the values. Change the recommendation to use [ document.body, document.documentElement ] and it's done.

[gijsroge]

Added a pull request that detects document.body & document.documentElement
So it adds support for Firefox and IE.

PR: #9

[nikoloza]

+1