Creates an option from the given parameters +params+.
See {Parameters for New Options}[optparse/option_params.rdoc].

The block, if given, is the handler for the created option.
When the option is encountered during command-line parsing,
the block is called with the argument given for the option, if any.
See {Option Handlers}[optparse/option_params.rdoc#label-Option+Handlers].
