Correct CHANGELOG entry regarding ActiveRecord::Base.include_root_in_json

Originally entered here: https://github.com/spree/spree/commit/e1a1d7a
Removed an extra space in the admin Products tab list.

Fixes #3399
[API] Allow for extra parameters to be passed through to a line item

Fixes #3404
[frontend] stub generate_spree_api_key! for user stub in products con spec
[frontend] correct promo discount rate due to changes in 6ff655269916607f00feef75dbdbfd8fa482f83c
Prevent AR NotFound error when creating new stock location without Spree::Config[:default_country_id] being set.
Use new_action.before callback to cleanup controller.
Fix tax zones country selects styles (remove button was under select)

[Fixes #3418]
Bump to Rails 3.2.14
Update rails version in README [ci skip]
Move Error Text calculation inside error block
Bump caypbara to 2.1.0:

* Add timeout into config/database.yml template to avoid SQLite3 DB locked out
* Use lenient non-exact setting for Capybara element matcher (same as 1.x)
Fix Frontend specs for capybara2.
[sample] Provide feedback when loading images

This can take a long time due to Paperclip doing its thing for all the different image styles.

Fixes #3395
[backend] Associate user with an order when NOT using guest checkout

Fixes #3335
Doesn't create redundant taxons root items.

Fixes #3413
Fixes #3417
extract searcher_class instantiation into module

searcher_class was being instantiated in the same way in home_controller
products_controller, and taxons_controller. This moves that code into a
new Spree::Core::ControllerHelpers::Search module.

Fixes #3420
Allow unshippable items on the order

So that users don't have their cart emptied every time they checkout to
payment in a store that doesn't have a delivery step

Fixes #3193
Wait for ajax from stock level population to complete in order_details_spec
Remove frontend's version of admin/plugin/fontawesome

This should only exist in backend