Add animation properties, functions, values

properties: animation-fill-mode
functions: cubic-bezier, steps
values: alternate-reverse, alternate, reverse, backwards, forwards, ease, ease-in-out, ease-in, ease-out, infinite, paused, running, start, end, step-start, step-end
Merge pull request #14 from i-akhmadullin/patch-2

Add animation properties, functions, values