Update activemerchant to requiring at least 1.31.x + ransack to 0.7.2

Fixes #2661
Bump rails to 3.2.13
Fix Spree.translations corruption of I18n cache

Fixes #2711
Mailers now require a from address, so we need to give defaults, using MailMethod.current
Correct MailMethod usage in mail_interceptor, order mailer and shipment mailer specs

Conflicts:
	core/spec/mailers/shipment_mailer_spec.rb
Invoke callbacks in #create and #update

Fixes #2736
Correct filename for diners club credit card icon

Fixes #2726

Conflicts:
	frontend/app/assets/images/credit_cards/icons/diners_club.png
Fix email validation error I18n symbol lookup

And include %{value} for interpolation in validation messages.
If not specifying a custom validation message or symbol this
will now use the same error message as rails' format validator.

This is the proper fix for the issue mentioned in PR #2364.

Fixes #2729
fix token field data to allow ' in the product name. Fails if product name is ex. "70's T-Shirt"

Fixes #2811
Return commerce_tracking in analytics_helper_spec so that completed_analytics_tag test passes
Use separate databases depending on the value of ENV['TC_AGENT_NUMBER']
Bump selenium-webdriver to 2.30.0
Allow sample to generate its own testing app
Bump to selenium-webdriver 2.32.0

Conflicts:
	common_spree_dependencies.rb
Correct documentation for title helper

Fixes #2878
Fix user role mass assignment from backend

This was broken by commit 175a23211337c9ba53242b54d19f84642989e984.

This specifically fixes two problems:
- #2905 Mass assignment exception when creating new users through backend
- #2904 Backend user gets logged into edited user account when changing
	password

Also update and unify core/auth admin user specs

- Add core admin create user spec
- Add auth admin create and edit user specs
- Merge badly namespaced auth user_spec into admin/users_spec
[core] Remove page! call in checkout spec
Check last inventory unit checkbox in shipments_spec

This should fix compatibility on postgresql+MySQL
Create MailMethod for password reset spec

Fixes "A sender (Return-Path, Sender or From) required to send a
message"

Fixes #2942
Use mock_model instead of stub for Spree::User

Fixes "undefined method 'model_name' for RSpec::Mocks::Mock:Class"

Fixes #2942