* TokenTransformDispatcher is now renamed to TokenTransformManager, and is
also turned into a base class
* SyncTokenTransformManager and AsyncTokenTransformManager subclass
TokenTransformManager and implement synchronous (phase 1,3) and asynchronous
(phase 2) transformation stages.
* Communication between stages uses the same chunk / end events as all the
other token stages.
* The AsyncTokenTransformManager now supports the creation of nested
AsyncTokenTransformManagers for template expansion.
The AsyncTokenTransformManager object takes on the responsibilities of a
preprocessor frame. Transforms are newly created (or potentially resurrected
from a cache), so that transforms do not have to worry about concurrency.
* The environment is pushed through to all transform managers and the
individual transforms.
The TokenTransformDispatcher now actually implements an asynchronous, phased
token transformation framework as described in
https://www.mediawiki.org/wiki/Future/Parser_development/Token_stream_transformations.
Additionally, the parser pipeline is now mostly held together using events.
The tokenizer still emits a lame single events with all tokens, as block-level
emission failed with scoping issues specific to the PEGJS parser generator.
All stages clean up when receiving the end tokens, so that the full pipeline
can be used for repeated parsing.
The QuoteTransformer is not yet 100% fixed to work with the new interface, and
the Cite extension is disabled for now pending adaptation. Bold-italic related
tests are failing currently.
