added sales by coupon report

initial version of sales by coupon report. Since multiple coupon codes
for a single order are stored comma separated, this report considers
them as 1 coupon. Handling multiple coupons within an order as
individual coupons with the report would be quite a bit more complex --
I think most stores force individual use on coupons anyway.
Filter WC_Cart->needs_payment() value
Show taxes if there are formatted taxes

The cart only checks if an order has tax when deciding to
display taxes. Subscriptions 1.2+ stores recurring taxes
separately, so when an order has a free trial period
and no sign-up fee, order tax will be 0 but the
recurring taxes should still be displayed.
Update Product Image Title w/ Variation Image for Lightbox
Cleaned up States in WC_Countries

Brazil and New Zealand were not in alphabetical order. Also was a duplicate in Brazil for 'RS' => __('Rio Grande do Sul', 'woocommerce').
Dutch translation refresh
Added Norwegian Nynorsk (nn_NO) translation
Merge pull request #1541 from frilyd/master

Added Norwegian Nynorsk translation to WooCommerce
Merge pull request #1535 from WooCommerceEU/master

Dutch translation refresh
readme
Fix updating when typing. Closes #1540.
Grammer. Closes #1538.
Merge pull request #1527 from thenbrent/master

Add filter to needs_payment() and display formatted taxes if set
Merge pull request #1530 from scottbasgaard/master

Update Product Image Title w/ Variation Image for Lightbox
Update Italian Translation
Variation stock should respect main inventory settings. Closes #1537.
Merge pull request #1544 from Giuseppe-Mazzapica/master

Update Italian Translation
readme and min
Fixes for italian translation

fixed errors and all 1.7.0 strings now translated
Merge pull request #1546 from Giuseppe-Mazzapica/master

fixes for italian translation