Invoice or Receipt for WooCommerce

Adds the option for collecting details related to issuing an invoice or simply a receipt in the WooCommerce checkout.

*****Please Read*****
Anyone who had installed the plugin in versions up to 1.1.0 will need to delete that plugin and install the newer one as the name and other parts of the code have been changed in order to be included in the WordPress repo.

== Changelog ==
= 1.2.3 =
* Fields changed from mandatory to non-mandatory
= 1.2.2 =
* Fix compilation files, mirror changes
= 1.2.1 =
* Fix _load text domain directive for WordPress versions 4.6+
= 1.2.0 =
* Deleted custom field #billing_company_name and add in its place added the default woocommerce field #billing_company, enabled script to make the fields required when “Invoice” is selected
= 1.1.0 =
* Add details to customer and administrator email, add column to order list view, add short column, add icon to the left of the word “Invoice”
= 1.0.3 =
* Added translation file, Greek / English translation
= 1.0.2 =
* Added indication inside the order with text for receipt or invoice
= 1.0.1 =
* Added dropdown selection instead of checkbox
= 1.0.0 =
* Initial release.