Provide methods on the already extant HashContext class.
As part of the long term effort to remove the resource type from PHP, the iterative hashing API provided by `hash_init()` et. al was converted to use object instances of the opaque class type `HashContext` for the PHP 7.2 release.
With the conversion to an object comes the opportunity to provide OOP interfaces to these APIs.
Note that the new update methods return the object instance to make using fluent method chaining easier rather that return bool or the number of bytes applied in the update. If they are unable to process the entire requested payload, they will throw an `Error` exception.
The psuedo classnames `Stream` and `StreamContext` here refer to what are currently resources wrapping `php_stream` and `php_stream_context`, respectively.
None. This does not change the API presented by the procedural hashing functions, and the only changes it makes to `HashContext` are additive.
8.1
Straight up/down vote.
After the project is implemented, this section should contain