internal: Try handling URLs in a consistent way. * Now URLs passed to, and returned from, routes will always be absolute URLs, i.e. URLs including the site root. * Validate the site root at config loading time to make sure it starts and ends with a slash. * Get rid of unused stuff. * Add tests.

[pytest]
norecursedirs = .* _darcs CVS .svn .git .hg *.egg-info dist build node_modules venv tmp* {args}