defined 4096_7168 code; the array-based ECC supports untransmitted parity bits

 * defined both h and g for 4096_7168 code from the hfec repo

 * the mutable array-based ECC now does not transmit the last 1K parity bits

 * I doubt that packet_size and punc_size in src/Haskell.hs are correct
Haskell.ecc_mutation no longer assumes that truncation of H corresponds to untransmitted bits; otherwise just code polishing