new: scrolling header cart

The more products in the cart, the less user-friendly the header
dropdown becomes. Giving it a `max-height` and making it scroll
resolves this. It also addresses an issue where using the Sticky header
/ Sticky nav option in the Storefront Designer extension would render
the bottom of the dropdown un-viewable when there are many products in
the cart, as it is always off-screen.

changelog.md

@@ -6,6 +6,7 @@
 * **New** - Pages now display featured images above the page title.
 * **New** - Revamped 404 page helpfulness to include product search, popular products and product ctegories.
 * **New** - Integration with WooCommerce Bundles extension.
+* **New** - Scrolling header cart.
 * **Fix** - Welcome screen now only visible to admins.
 * **Fix** - Horizontal scroll bar in Safari at small sizes.
 * **Fix** - Pay for order screen layout when using full width page template on my account.

inc/woocommerce/css/woocommerce.scss

@@ -73,6 +73,11 @@
 	.widget_shopping_cart {
 		display: none;
 		background-color: #2c2d33;
+
+		.product_list_widget {
+			max-height: 15em;
+			overflow: scroll;
+		}
 	}
 }