[api] Fix zones_controller_spec
Only include eligible promotions in promo_total
Removes deprecation warning during preferable_spec run

Fixes #2174
taxon autocomplete display pretty_name instead of name

Fixes #2178
orders should only display variant text on order_details page

Fixes #2170
Add patience to admin/configuration/states_spec
no need for 1.9.2 statement inside gc_hacks anymore
Only show eligible adjustment in admin order edit view
Remove 1.8.7 support in travis 

Since we're having intermittent failures with Travis and 1.8.7 we should just strike this for now.
[Fixes #2184] CreditCard number is no longer blank when processing
payments. Thanks to @liufengyun for the solution
Explicitly set Spree::CreditCard table name within spree/payments.rb

Fixes #2130
Remove check for with_state call in order_spec

Related to #2184
Remove gc_hacks file

The 'hacks' in this file were causing the GC for Ruby to be disabled, which was causing memory to balloon out of control when running the tests. Without this file, memory consumption is normal.

Proof: https://gist.github.com/4028714
Adding return authorization API

Closes #2163
Restrict admin-y actions on return authorizations to just admins

Related to #2163
[api] Restrict all return authorization actions

Relates to #2163
Adding Notes about Promo Checkout Controller Override

Fixes #2182

Conflicts:

	core/app/controllers/spree/checkout_controller.rb
Refactor out methods to product class that control if a product is on sale or on display.

Fixes #2167
Adding promotion usage information to the admin

Fixes #2193
stub has_available_shipment calls in tests

This method is caused unwanted side-effects

Related to #2191