Rename files, reorder structs, remove annoying BorrowedBinaryData type. This is basically a cleanup change. Also it adds tests. - Renames the files with Questions and Answers to question and answer. - Reorders the structs in those files to put the important ones first. - Removes the BorrowedBinaryData type. It was a bad idea all along. Instead, we just use (&[u8], u8). - Adds some tests because I just can't help myself.