Change sysly scheduling to on the half-hour

Arguably the entire boolean condition should be up to the user, but for now we just put it on a 48 times/day cycle.

Add `j` short alias

Even more terse than J.

Only little clean-ups, really.

Should be hardly discernable if anyone is using this..but may help new code readers.

Portability fixes

Should install with nimble on Linux & OS X now with nim-devel & nim-1.6

Calls randomize in release build to actually de-sync load.

Various new features & polishing

Allow client program to configure the rounded period used for matching & logs all the way to nanosecond resolution (though the idea starts to break down around 10usec). Test this carefully in test/.

Generalize crup.sh to not depend upon my personal convention.

Add DoSync counterpart to Do action where the latter fork()s and former does not.

Rename setClock -> rdateSet to be more specific for NTP/etc users.

Add some test/ evaluation programs (that double as one experimental probe into Linux scheduler policies).