- Add PHP League's Container package via Composer.
- Add an ObjectContainer class that encapsulates all the configuration
and insulates the codebase from the concrete DI engine used.
- Add an improved ReflectionContainer class that will allow to
register individual classes as singletons while autowiring.
- Use ObjectContainer to resolve the WooCommerce class, everything
instantiated with "new" inside it, and all singletons that are
usually obtained via WC() function.
- Introduce the CustomerProvider class.
- Introduce a service provider to resolve WC_Queue_Interface,
this replaces the WC_Queue class.
- Mark as obsolete all the replaced "instance()" methods,
and the entire WC_Queue class.
To take care of instantiating a canonical job queue for use across
all of WooCommerce, and by 3rd party code.
Also use this new API for enqueuing webhooks instead of raw Action
Scheduler APIs.
Nestor Soriano
Gerhard Potgieter
Brent Shepherd