Addig a new random seed for external tests.
I added a wrapper around the siphash() function to make calling it a
little bit safer at least.
BIT-1612 #merged
* origin/topic/johanna/bit-1612:
HLL: Fix missing typecast in test case.
Remove the -K/-J options for setting keys.
Add test checking the quality of HLL by adding a lot of elements.
Fix serializing probabilistic hashers.
Baseline updates after hash function change.
Also switch BloomFilters from H3 to siphash.
Change Hashing from H3 to Siphash.
HLL: Remove unnecessary comparison.
Hyperloglog: change calculation of Rho
This commit mostly changes the hash function that is used for Internal
hashing of data < 36 bytes from H3 to Siphash. This change is motivated
by the fact that it turns out that H3 apparently does not deliver a very
good source of data uniqueness; running HLL with H3 as a hashing
function results in quite poor results (up to of 75% off in my tests).
In difference, running HLL with Siphash (or HMAC-MD5) changes this
factor to ~2%.
This also fixes a long-standing bug in Hash.h which truncated our hash
values to 32 bit on most machines.
Furthermore, it once again fixes a problem with the Rank function in
HLL.
