YITH WooCommerce Gift Cards Premium 4.22.0

* New: added option to enable and disable the currency switcher integrations
* Tweak: choose date using a date picker when create a gift card at backend
* Tweak: new status "not sent" for gift card which have not been sent yet
* Tweak: disable autocomplete of the field "Delivery Date" on frontend
* Tweak: created procedure of backup before to proceed with the update of delivery date postmeta
* Tweak: display the currency symbol when the manual amount is zero
* Tweak: added a new icon in the "Add recipients" link
* Update: updated language file .pot
* Update: updated Spanish language file
* Update: updated Dutch language file
* Update: updated the Smart Coupons integration settings description.
* Update: updated WPML config
* Fix: fixed issue adding physical product and virtual gift cards
* Fix: fixed the date format conflict with the send delayed gift cards method
* Fix: fixed wrong usage of variable ywgc_data
* Fix: expiration date set to unlimited always
* Fix: fixed problems with the French translation
* Dev: added a filter to the general settings options yith_ywgc_general_options_array
* Dev: added new filter yith_ywgc_apply_gift_card_discount_before_cart_total
* Dev: added new filter to the cron job hour yith_ywgc_send_scheduled_gift_cards_hour
* Dev: added new filter yith_gift_cards_format_number_of_decimals

New: option to prevent purchasing of virtual gift card and physical products in the same order
Update: Updated .pot file
Update: italian language file
Update: Spanish language file
Update: updating and fixing some string in Dutch
Fix: prevent notice when date is not an object of DateTime
Fix: string "Choose the delivery date" is not translatable
Fix: notice undefined index 'ywgc_amount'
Fix: fixing an issue with the gift card codes
Fix: chaging postponed delivery placeholder
Dev: new hook 'ywgc_before_sent_email_gift_card_notification'
Dev: updating a string
Dev: new filter 'yith_wcgc_set_gift_card_as_sent'

* New: support to WordPress 5.0-RC3
* New: added a new option to select the date format in the plugin
* New: shortcode "yith_wcgc_show_gift_card_list" to print the gift card list
* New: added a new option to disable the "Click here for the discount" button in the email if needed
* Tweak: custom filter to create gift card. No gift card created for processing status with Cash on delivery method
* Tweak: now the add to cart message when the product is added as a gift shows the product name
* Tweak: now the gift this product buttons in the shop are not shown in out of stock products
* Tweak: filter to modify the arguments to display design categories
* Tweak: changed admin setting text
* Tweak: new settings to display email button on gift card code email sent
* Update: Updated Spanish language
* Update: updated German .po file
* Update: updated plugin FW to version 3.1.5
* Fix: prevent js error if ywgc_data is not defined
* Fix: prevent js errors when variables are not set
* Fix: Fixed error in the automatic discount template
* Fix: allow displaying message break lines on the gift card page
* Fix: delete backend link in the gift card code when an order is autocompleted
* Fix: Fixed some errors with the empty() method and the get_option
* Dev: new filter 'yith_ywgc_show_all_design_text' for "Show all designs"
* Dev: new filter 'yith_wcgc_deny_gift_card_email'
* Dev: filter to stop sending gift card code email by default
* Dev: new filter 'yith_wcgc_force_generate_manually_code_always'
* Dev: added a new hook yith_ywgc_after_gift_card_generation_save
* Dev: added some product checks
* Dev: added the parameter $context to the filter ywgc_display_price_template
* Dev: change a variable
* Dev: duplicate an action with different params
* Dev: added a new filter to the default email subject text
* Dev: changed some strings in the smart coupons transfer option
* Dev: added a new condition to the unlink files
* Dev: added WPML config file
* Dev: added new condition to check the gift card title
* Dev: added a new filter ywgc_email_notify_customer_recipient_email
* Dev: fixed a non-numeric value warning
* Tweak: filters to hide price on gift card email sending and PDF
* Tweak: different email for BCC gift card code email