Fix active button state.

When using Twenty Twelve, the purchase button loses its border in the active state. This causes a jarring visual effect. Twenty Twelve adds `border: none` to the `input[type="submit"]:active` selector which causes the problem. Explicitly adding a border to the active state of the EDD purchase button fixes the issue.

Although this is EDD conflicting with a specific theme, I think it is an important change as it will help fix conflicts with Twenty Twelve child themes and make the button styling more stable across a number of themes.
Merge pull request #1338 from tollmanz/active-button-styling

Fix active button state.
wp_die() if no payments found when verifying download link
Ensure correct timezone is used for strtotime(). #1334
Ensure correct days of the months are used. #1003
Correct dates so API can correctly cross year boundaries. Closes #1003
strtolower bootstrap
Revert symlinks update to fix unit tests
Tweak WP_Session
Whitespace
Fix year/month folders. Closes #1324
New HiDPI admin download icons
Merge pull request #1342 from themeblvd/master

New HiDPI Downloads menu and CPT admin icons. A little more clean and WordPress-ish.
Add cart update processing function. #1199
Allow item to be added to cart even if it exists already. #1199
INtroduce edd_item_quanities_enabled() (for testing). #1199
First pass at refactor of edd_get_cart_item_quantity. #1199
Add form elements to checkout cart. #1199
Process cart updates. #1199
Add cart item quantity functions and set quantity when adding items to the cart. #1199