Add compose function which supports generators

[tomkis]

The function is especially very useful with immutable data structures. May be a fork of redux compose function. The support of generators should be transparent yet the function should always return generator.

/**
 * @param {...Function} functions to be composed, may be either function* or function
 * @returns  {Function} Functions which takes initial argument and returns iterable
 */
function* compose(...fns) { }

Composition is right to left so that it's more easier for people to use:
compose(f, g)(x) is actually (g ∘ f)(x)