This version is a  fairly  generic  NTT,  except it does require the
compiler to supply some sort of 64 bit integer.

GNU C does provide this, although on a 32 bit processor it's not  as
fast  as  if you made a processor specific version.  (ie:  like I've
done with the DJGPP486 and DJGPP586 versions.)

Some 32 bit compilers produce buggy 64 bit 'long long'  code.   I've
tried to minimize the risk, but I can't guarantee that it'll work on
your system.  All I can say is that it works under DJGPP 2.7.2.1.

If  your  compiler supplies 'inline' functions, you'll probably want
to make the modmath.h and crt.h functions 'inline'.


