Version 0.5.0

UPGRADE WITH CAUTION

This is the first release that requires PHP 7. The internals have been rewritten
from the ground up. Some features available in previous releases are no longer
available as substitute functionality has not yet been added.

There are far too many changes to list here individually, however much of the
kernel API remains the same.

• [BC] Channels and streams have been removed from the core package.
• [BC] Recoil::run() has been removed (see ReactKernel::start()).

Kernel API changes:

• [BC] kernel() has been removed.
• [BC] eventLoop() is only available when using ReactKernel.
• [BC] return_() has been removed, as generators can return values in PHP 7.
• [BC] throw_() has been removed.
• [BC] finally_() has been removed.
• [BC] noop() has been removed.
• [BC] stop() has been removed.
• [BC] select() now operates on PHP streams, rather than strands.
• [NEW] Added read() and write()
• [NEW] Added callback()
• [NEW] Added link() and unlink()
• [NEW] Added adopt()
• [NEW] Added any(), some() and first()