WooCommerce btn styles, cart/checkout/acct pages

WooCommerce btn styles, cart/checkout/acct pages

The cart/checkout/account pages were still showing the right site
sidebar because they do not count as "woocommerce pages" as far
as woocommerce is concerned. Thus they do not utilize the
woocommerce.php template file. Now the proper markup has been
inserted into index.php > interior-page.php section for those pages

Also added button styles for some of the WC buttons which were
still greyed out.