feature : taxons meta tags and title

Fixes #2787

Conflicts:
	frontend/spec/requests/taxons_spec.rb
Fixes orders#show title for i18n cases

Fixes #2784
Remove ancient TODO from bottom of orders_controller_spec
When a calculator is using a preference of type :text, a textarea is shown. The calculator.js should disable/enable this textarea the same as the input from a preference of any other type.

Fixes #2782

Conflicts:
	backend/app/assets/javascripts/admin/calculator.js
Fix a missing icon class [Fixes #2638]

Fixes #2775
Reduce minimum characters required for variant autocomplete (from 4 to 3)

Fixes #2774
Add US Military state codes to default states

Fixes #2769
Wait a bit longer after update in promotion_adjustments_spec before adding an adjustment
Fix error when running 'rake db:seed'
Fix random encoding issue with spree/states.rb sample data
Revert "Fix error when running 'rake db:seed'"

This reverts commit 6725f9f666e6f2e99fc1baaab006fb83defd220d.
Remove apply button as it duplicates update buttons behavior. Discussed in issue #2720
Fix broken specs caused by 496d1ce