Update README for 2-3-stable
Bump to 2.3.0
[frontend] Make thank_you_for_your_order message much smaller

It's not a header, just a notice. It doesn't need to be as big as the order number.
Bump to Rails 4.1.2
Add basic Devise configuration to stop dummy app warning
Clear all CHANGELOGs
Bump to 2.4.0.beta