MOV: moved the try32/try64 attacks (mfkey32/mfkey64) into the nonce2key.c file
CHG: added @marshmellow42 changes to hf mfu dump layout.
ADD: an extra call to BigBuf_free in readcard.. just to make sure that it doesn't leak memory.
ADD: expermimental call to "try32" for "hf mf sim x".