Bug fixes & minor define-controls

Fix a bad bug of histogramming x instead of unshifted x0 and make
MovingStat work with OrderStats

Guard cligen usage with defined(useCligen) {to make .nimble not lie} and
also introduce -d:portablensort to deactivate Intel-specific PEXT32/64 nsort
optimizations. { Yes, yes..should just auto-detect/cpuid/etc. }

Make a couple test programs nicer.