mild overhaul of how scripts and templates are structured and loaded

- now only title and body are updated on client render
- scripts middleware removed, since it is probably better to rely on
static server
- simpler function for writing script bundle and map to file
- relies on updated client-side connection config in racer browser
channel
- added Tail template that is added after scripts
- set some views as serverOnly so they don't add to the bundle
- include bundle as json in its own script, which is probably better
and at least avoids locking up the elements tab in chrome dev tools
cleanup previous bundle and map files in development
explicit call to Component::getAttribute instead of rendering by default; don't emit component hooks on static render; singleton components use the page as parent and model scope
use new racer Model::eventContext to clean up component model listeners on destroy
actually hooks are needed on component html rendering sometimes, so emit them