Start Flask-Roots.

This is mainly copied from Spoon, and is not
functional in its current form.
Add Ruby/Node/Bower paths to activate
Explicit bower directory
Register 'acl' extension
Roots are (barely) functional
Tiny tweaks
`activate` adds Flask-Roots bin to $PATH
Refactor Roots as extension
Use FLASK_INSTANCE_PATH; Roots takes over config
Set app.instance_path
Persistant SECRET_KEY
Docs
make_config takes a name
Manually extract roots attrs
spoon.main -> spoon.web
Adapt bin/manage to new config structure
Little tweaks
Notes
Locate Flask app via roots.py
Take over bin/manage from Spoon