Titan: scrypt-N Proof Of Concept
Titan: different hardware diff for different N
Titan: add option "scrypt-n"
Titan: scratchbuf for N > 16 does not fit on stack, use malloc
Titan: adjust hardware dificulty for N=12 & 13
  RPi was not able to keep up verifying nonces at that rate.
Merge branch 'titan-scrypt-N' into knc