Fixed bug with uin64 compare fn() call

removed copy/paste but introduce a few days ago that cause uint64 to
use uint16 compare function…
Added test support, rdb_dump fix

Woohoo, Unit testing is alive.
Only four basic tests now configured, but more is on the way.
soon we will have a standard test to exercise all data operations on
all types of data… building confidence was never so much fun