Add BCH support to the repo

[nttoole]

Integrate existing support for BCH (Bose, Chaudhuri, Hocquenghem) - provided by Kabir Marwah (ASU) - into the DSN repository.

[MJJoyce]

Note, for tracking purposes and to ensure adequate credit is given, this was contributed by ASU (with minor modifications) through email and phone conversations. At the minimum, I'm aware of @kmarwah and Tyler O'Brien being two of the original developers of the code.

@kmarwah, if the above is incorrect let me know! Similarly, if you know Tyler's Github username put it in here as well!