I have modified randmtzig.c to use dSFMT's double precision random
numbers. It ends up using the randomness from the 52-bit Mantissa.
The code is changed to reflect this slightly lower precision.

This makes individual calls to randn() about 25% faster.

Minor cleanups to randmtzig.c.

I have modified randmtzig.c to use dSFMT's double precision random
numbers. It ends up using the randomness from the 52-bit Mantissa.
The code is changed to reflect this slightly lower precision.

This makes individual calls to randn() about 25% faster.

Use 64-bit ints for randmtzig fill functions.
Minor cleanups to randmtzig.c.

Minor changes to randmtzig.c for clarity.