We already have a LICENSE file that covers the Zig Standard Library. We
no longer need to remind everyone that the license is MIT in every single
file.
Previously this was introduced to clarify the situation for a fork of
Zig that made Zig's LICENSE file harder to find, and replaced it with
their own license that required annual payments to their company.
However that fork now appears to be dead. So there is no need to
reinforce the copyright notice in every single file.
The main goal here is to make the function pointers comptime, so that we
don't have to do the crazy stuff with async function frames.
Since InStream, OutStream, and SeekableStream are already generic
across error sets, it's not really worse to make them generic across the
vtable as well.
See #764 for the open issue acknowledging that using generics for these
abstractions is a design flaw.
See #130 for the efforts to make these abstractions non-generic.
This commit also changes the OutStream API so that `write` returns
number of bytes written, and `writeAll` is the one that loops until the
whole buffer is written.
