Spree namespace for all translations and use the Spree.t method everywhere.

Correct user_signed_in? to spree_user_signed_in?.
Fix Romanian plural forms.
Better integrate admin views with Spree 2.0
(cherry picked from commit c326a2cd09335ea2c147734d65e38c1c78f8bcf1)

Conflicts:
	app/controllers/spree/admin/review_settings_controller.rb
	app/controllers/spree/admin/reviews_controller.rb
	app/controllers/spree/reviews_controller.rb
	app/helpers/spree/reviews_helper.rb
	app/overrides/add_reviews_to_admin_configuration_menu.rb
	app/overrides/add_reviews_to_admin_configuration_sidebar.rb
	app/views/spree/admin/feedback_reviews/index.html.erb
	app/views/spree/admin/review_settings/edit.html.erb
	app/views/spree/admin/review_settings/show.html.erb
	app/views/spree/admin/reviews/edit.html.erb
	app/views/spree/admin/reviews/index.html.erb
	app/views/spree/feedback_reviews/_form.html.erb
	app/views/spree/feedback_reviews/_summary.html.erb
	app/views/spree/reviews/_fine_print.html.erb
	app/views/spree/reviews/_form.html.erb
	app/views/spree/reviews/new.html.erb
	app/views/spree/reviews/submissionguidelines.html.erb
	app/views/spree/reviews/terms.html.erb
	app/views/spree/shared/_rating.html.erb
	app/views/spree/shared/_review.html.erb
	app/views/spree/shared/_review_summary.html.erb
	app/views/spree/shared/_reviews.html.erb
	config/locales/de-CH.yml
	config/locales/de.yml
	config/locales/en-GB.yml
	config/locales/en.yml
	config/locales/es.yml
	config/locales/fr.yml
	config/locales/pl.yml
	config/locales/pt-BR.yml
	config/locales/pt.yml
	config/locales/ro.yml
	config/locales/ru.yml
	spec/features/admin_spec.rb
	spec/spec_helper.rb
	spree_reviews.gemspec
Update syntax to work on Ruby 1.9.3.
(cherry picked from commit 53ea7d2cfbd171275e5233b4b4aa54b93ee272c9)
Add missing translation.
Pending features to make tests pass.

This tests don't seems to have been updated.