Fix CreditCard scope in Order

Model.all is deprecated in Rails 4
Clean DEPRECATION WARNINGS from within spree code

Most of these are related to `find_by` with options and `Model.all`
Use a awesome_nested_set github fork for Rails 4

Help us get rid of the thousands of warnings due to an AR deprecation on
how to access connection from an instance, no rc for that gem has been
relased at this moment
Upgrade jquery-rails to ~> 3.0.0

So that users can try rails4 branch more easily, without errors when
bundling spree within a Rails 4 app

[Fixes #3178] [Fixes #3227]