Revision history for Async-Stream

0.01    24.06.17
        First version, released on an unsuspecting world.

0.03    24.06.17
        Adding arguments validation

0.04    24.06.17
        Fix for bug with several request to same item

0.05    07.07.17
        rename public method sort -> arrange, cut_sort -> cut_arrange, each -> for_each
        add posobility to make streams with prefetching.