Spontaneous.init should return the site instance
Allow for mounting Rack apps into the back, not just Sinatra apps
Fix Fog deprecation warning
Add a default proc to prototype set
Pages should recognise their own outputs
Symbols should select as UIDs
Page controllers are now full Sinatra instances.

This along with consistent inheritance for the controller classes allows site-wide configuration
of request handlers (e.g. for session config & middleware). Fixes #27