Todo

Classes summary

prdd_addon_compatibility_class	check the class and remove if it is not necessary

prdd_addon_compatibility_class	`__construct()`	check the function and remove if it is not necessary
prdd_addon_compatibility_class	`prdd_add_wpa_prices()`	check the function when it is used and remove if it is not necessary
prdd_cart	`prdd_add_cart_item()`	Unused function. Need to check and delete it.
PRDD_Email_Delivery_Rescheduled	`init_form_fields()`	Unused function. Need to check and delete it.
PRDD_Email_Delivery_Rescheduled_Admin	`init_form_fields()`	Unused function. Need to check and delete it.
prdd_timeslot_price	`timeslot_price_div()`	Unused function.
PRDD_View_Deliveries_Table	`search_box()`	Function is not necessary