bake: Optimize the bake by not using custom classes for passing info. See previous changeset about pickling performance between processes. Now just use plain standard structures, or the new `fastpickle` when needed.

syntax: glob
*.pyc
venv
tags
build/lib
util/messages/_cache
util/messages/_counter
dist
docs/_cache
docs/_counter
docs/bower_components
docs/node_modules
piecrust.egg-info
piecrust/__version__.py

docs