iterrr: extensible iterator library

[hamidrb80]

> Looks good to me!

**see new version `0.2.1`** with removed `i` prefix and infix style custom 
idents `=>`, you can write:
    
    
    (1..10) |> map(n => _ )
    (1..10) |> map((a1, a2, ...) => _ )
    
    
    Run