Add PHPUnit to require-dev

Consistent method semantics and documentation

Consistent pipe() semantics for closed and closing streams

Consistent end event semantics (EOF)

Consistent event arguments and documentation

Fix removing resource from loop after buffer is completely drained

Remove custom full-drain event

Improves test coverage

The Buffer can now be injected into the Stream (or be used standalone)

Consistent close behavior for Buffer

Forward close event only once

# Conflicts:
# src/Stream.php

Do not construct ErrorException from within error handler

Only emit permanent errors and otherwise keep retrying

isset() is a language construct and avoids the overhead of function
calls

Ignore empty writes to Buffer

Remove branch-alias definition as per reactphp/react#343

Add benchmarking script to measure throughput in CI

Revert "BufferedSink: Remove progress notifications"

Emit error and close when reading from stream fails

Do not emit empty data event if nothing has been read

php benchmark-throughput.php -i <(yes)

BufferedSink: Remove progress notifications

Fixed double-writes when write() is called during 'drain' event

[RFC] Improve compatibility with legacy versions

HHVM does not support, nor require, unbuffered read operations

This reverts commit affeaedac3f999457179407c6897b1ca3e29db75.

Set read buffer to 0