http: Rename 'path' to 'static_file_path'
http: Include registry name in docs
http: Rename 'linkify()' to 'get_root_url()'
http: Rename 'setup_routes()' to 'get_request_handlers()'
http: Improve router attribute docstrings
http: Import modules, not attributes
http: Use single quotes
http: Avoid tornado import before extension is loaded, group all handlers
http: Simplify extension loading

...and fix breakage I just made myself.
http: More consistent use of 'request handler'
http: Simplify test imports
http: Split tests into three files
http: Change registry key to match docs
http: Give routers access to the core API
http: Move Mopidy request handlers to a MopidyHttpRouter
http: Enforce router's URL namespace