routing: Simplify how routes are defined. * No more declaring the type of route parameters -- the sources and generators already know what type each parameter is supposed to be. * Same for variadic parameters -- we know already. * Update cache version to force a clear reload of the config. * Update tests. TODO: simplify code in the `Route` class to use source or generator transparently.

*.pyc
*.egg-info
.cache
__pycache__
venv
tags
bower_components
node_modules
build/lib
util/messages/_cache
util/messages/_counter
dist
docs/_cache
docs/_counter
foodtruck/static
piecrust.egg-info
piecrust/__version__.py
.ropeproject