0.9.3   Fixed call and put options (for American), however they still do NOT tally with
            the function BinaryTreeOption() in library(fOptions), which may be a different
            algorithm. For the functions BscdOptionPrice() and BscdOptionEarly(), we added
            a parameter subMtx that allows a user to replace the stockMtx=model$sRate*S.
            The reason is to be able to reproduce Kang's (2004) case study on "Valuing
            Flexibilities in the development of New Songdo City (NSC)" in the R Markdown
            file "Kang_02_nsc_Bscd". Also, this file validates the "ca" output from the
            function BscdOptionPrice().