Adding anima

Description: With Anima it's easy to animate over a hundred objects at
a time. Each item can have it's mass and viscosity to emulate reallife
objects!
Source: https://github.com/lvivski/anima
License: MIT
Author: Yehor Lvivski (https://github.com/lvivski)
Merge pull request #3337 from JGallardo/master

Adding anima