Remove reference to (removed) aspen.execution
Remove sphinx autodoc for other removed modules
Merge pull request #383 from gratipay/nuke_execution_docs

Remove reference to (removed) aspen.execution
Merge pull request #384 from gratipay/format-for-100

Format a file for 100 char lines
Merge pull request #385 from gratipay/media_type_default

remove request.website
Merge pull request #386 from gratipay/format-for-100

remove request.website
Prune unused imports
Failing tests for dispatch returning a result
Return a result from dispatcher.dispatch
Stop abusing request.headers

Instead of overloading request.headers for implicit content negotiation
and autoindexing, store the needed info in a dispatch_result.extra dict,
passing dispatch_result around as needed.
Remove dependence on request.uri in dispatcher
Move setting of request.fs out of dispatcher
Stop passing request to dispatch entirely
Get test suite passing again
Remove dependency on website.media_type_default
Remove dependency on website.indices
Remove dependency on website.www_root
Remove website.list_directories & .ours_or_theirs
Remove website entirely from dispatcher
Remove request.fs

Now that we expose dispatch_result to simplates and in the algorithm
state, we no longer need to store the filesystem path at request.fs.
Yay for modularity!