Deprecate woocommerce_admin_css action - it's pointless

Will be removed in 2.4. Closes #6456
[2.2] Ensure rate is double

Fixes #6442
Re-do coupon free shipping option desc issue #6391

I didn’t update the POT as was having some poedit issues
Made template debug mode set WC_TEMPLATE_DEBUG_MODE constant and remove all overrides for all template loading functions.

Closes #6436
Prevent order statuses affecting other queries.

Closes #6437
get_pagenum_link is wrapped in an escape

Closes #6407
Adding @global docblock for proper code validation
get_page() is deprecated since 3.5.0
Merge pull request #6467 from tivnet/patch-3

get_page() is deprecated since 3.5.0
Remove all calls to get_page(), as it was deprecated on WordPress 3.5.0
Merge pull request #6469 from bordoni/deprecate/get_page

Remove all calls to get_page(), as it was deprecated on WordPress 3.5.0
[2.2] Core still has issues dealing with pad_counts + parent when getting categories.

Workaround by not hiding empty cats, then filter the returned list
using wp_list_filter. Fixes #6459
[2.2] When formatting meta data for display, suffix items to prevent issues when there are multiple values for the same meta key

Fixes #6404
move proceed to checkout button. closes #5496
Refund report changes

1. Ensure refund order_total is negative and reflects the full amount,
not just line items
2. Ensure transients are cleared when doing refunds
3. sales-reports order types so we can exclude refunds from pure
‘sales’ reporting
4. Tweak placement of refunds in legend.

Closes #6411
[2.2] Unhook save_meta_boxes after first successful run to prevent race conditions

Fixes #6376
Merge pull request #6463 from tivnet/patch-2

Adding "global" docblock for proper code validation
Merge pull request #6457 from bryceadams/master

Re-do coupon free shipping option desc issue #6391
Small tweak on text in #6457
Display order & item totals with correct currency

If a store changes currency or is using an extension which allows for
purchasing in multiple currencies, the currency symbol displayed on the
Edit Order admin screen may be incorrect for previous orders because
it uses the `wc_price()` fallback, which is the site wide currency
rather than the currency for that specific order. This fixes that.