replaced multiple sub-codes with single option sub-code

the LET, Keep and Question sub-codes will never be used with the same
code, so only one bit is needed for these three sub-codes and therefore
these sub-codes were replaced with the Option sub-code

added an option name variable to table entries along with an access
function to be used for commands that use the new option sub-code so
that the appropriate sub-code name can be output for testing

rearranged the table entries so that each entry is consistent with
each other (put the names on their own, second, line)