SMHasher: increased ZeroKeyTest size from 64K to 256K and added progress indicator
SMHasher: increased ZeroKeyTest size from 64K to 256K and added progress indicator

In very strange way in the ZeroKeyTest 64-bit and longer hashes are
processed ~20x faster than 32-bit ones, so processing of 256K keys with
32-bit hash require about 60 seconds. Hence i added progress indicator.
Testing only 64K keys provides not enough results to check, since only
0.50 collisions are expected.

Bulat-Ziganshin/FARSH,Bulat-Ziganshin/FARSH