2.0.0 RC1

This is a release candidate for Amp v2.0.0. Please test it carefully and provide any feedback you have.

• Amp\reactor() has been replaced with Amp\Loop::set() and Amp\Loop::get().
• Amp\driver() has been replaced with Amp\Loop\Factory::create().
• Amp\tick() no longer exists and doesn't have a replacement. Ticks are an internal detail.
• Functions for creating and managing watchers are now static methods of Amp\Loop instead of functions in the Amp namespace.
  • once() is now delay() and immediately() is defer().
  • Parameter order for delay() and repeat() has been changed.
  • reference() and unreference() have been added.
• Amp\Pause has been renamed to Amp\Delayed and accepts an optional resolution value now. Additionally reference() and unreference() methods have been added.
• Promise accepting functions have been moved to the Amp\Promise namespace.
• Amp\Promise\some() accepts an additional $required parameter.
• Amp\call(), Amp\asyncCall(), Amp\coroutine() and Amp\asyncCoroutine() have been added.
• Amp\resolve() has been removed, use Amp\call() instead.
• Promise::when() has been renamed to Promise::onResolve()
• Promise::watch() has been removed, use Amp\Iterator, amphp/byte-stream or a custom implementation that implements Amp\Promise instead and provides dedicated APIs to access the previously data shared via the watch() mechanism.
• Amp\Iterator, Amp\Emitter and Amp\Producer have been added with several functions in the Amp\Iterator namespace.
• Various other changes.