use content tag instead of html

add an icon for volume pricing tab

update translation for spree 2 namespacing

add whitespace to product volume pricing view

update volume pricing translations globally for spree 2

lowercase, not uppercase spree for locales

use spree translation for current tab condition

include blank and add select2 to discount select

update actions to use spree delete button
Fixes #68

Conflicts:
	app/views/spree/products/_volume_pricing.html.erb