Updated Group Editor.

Updated Group Editor. Added automatic change in availability when using a mathematical expression for changing the number of goods. When specifying a value, for example "-10", if the total number of products is less than "0", then the value "Out of stock" will be set. The function is active only if the forced change of the status "Available" is not specified.

Added an option for the number of characters in the protective image (captcha) for comments.
Added group editing.
A new method for displaying the list of categories in the Store has been added.