Document a way to detect faulty 3D support

[FagnerMartinsBrack]

One may want to use advanced 3d features (like data-z, rotate-x and rotate-y) which are fully supported for some devices, but not supported in others. In this case it is wise to delegate the support condition to the developer, who knows better which features his target devices support relative to the presentation he created. If it doesn't support, just fail gracefully.

Currently the browser support is hard-coded into the core, but there should be a way to expose the support as an API to be able to extend or override it.

The idea is to detect faulty 3D support by user agent sniffing in a per use-case basis.

It would also prevent this kind of problem: #164 (comment)

Maybe something to be done along with #158?
Thoughts?