Add WC_Product::get_formatted_name()

For #2788
Add WC_Product_Variation::get_formatted_name()

For #2788
Deprecate woocommerce_get_formatted_product_name()

For #2788
Update woocommerce_get_formatted_product_name use

To use new WC_Product::get_formatted_name() function. For #2788
Update phpdoc
Spanish translation update

Spanish translation extended and improved.
Ensure product exists on downloads information.
Merge pull request #3052 from warrendholmes/master

Ensure product exists in the downloads panel.
Remove loader and change zindex Closes #3057
Fix 3.6. Closes #3061.
Move click tracking code so it doesn't need a loop. Closes #3058
Better validation Closes #3059.
Reverse breadcrumbs Closes #3065.
validation
ruble Closes #3072.
Version bump
SKU: search case insensitive support
Master branch is now 2.1-bleeding
Removed Piwik integration from core
Removed ShareYourCart integration from core. Closes #2937