Overview of Version 2 Product Options

FishCart now supports product options.  These are quite flexible,
supporting absolute and relative pricing, as well as absolute or
relative SKU modifications.

The option prices can either be relative to the base product price,
or it can replace it completely.

There are four ways to have the product option SKU replace the 
base product SKU.

1. The option SKU can prepend to the base SKU.
2. The option SKU can append to the base SKU.
3. The option SKU can completely replace the base product SKU.
4.  The product option SKU can be substituted into a pattern 
    given in the base SKU.  That is, if the base SKU is given as
    '123-ZZZ-789', the product option can be specified to replace
	the pattern 'ZZZ' with the SKU pattern given in the option.
	Different options of the same product can have different 
	replacement patterns, allowing for very complex SKU management.

Options are tighly bound to a particular product.  To add options to a 
product, first add the product, then modify the product in the /maint
section of the cart.  Links to add or modify options are at the top of 
the modification page for each product.

Options can be grouped together to work as a unit.  When the options
are defined, an integer number can be entered in the group field to
logically group this option with others on the same product.  It is 
up to the maintainer to specify group numbers to associate the desired
options together.

If the group value is zero or blank, the option is considered standalone
and is not associated with other options against the same product.

When grouped, the option description is taken from the first option
read in the group.

Thus, three product options for a given product with a group value
of '1' will be associated together.  The group can be specified to 
permit only one of the options to be checked (radio buttons), or it
can be set to allow any of the options to be set (checkboxes).

Options, or option groups, can be required, or they can be optional.

Options, or option groups, can be set to default to a quantity of 1,
or a quantity can be entered.

Please note that some combinations of the above product option features
are mutually exclusive.  It is up to the cart maintainer to make sure 
that the options as defined make sense in how they are specified.