Work on better documentation & update distributed config

This is still a work in progress. (I should, at least, write 3 man pages and install the config from nimble as lc does, and perhaps even optionally install symbolic links for pd/pf/pk/pw/sc out of nimble for folks doing quick try-outs.)

Bug fix for --newest/--oldest

Should work as intended now. Stiff iffy-tie breaking if PID wraparound can happen, but then again how many ties within the 10ms jiffy are likely?

Add -A to `procs find`

Add in a short -A option alternative for recent --age filter rule.

Add older/younger process age filter

This is an interesting feature for all the reasons that process age itself might be, or --oldest or --newest and so on.

While processes can live & die, pd -sab $(pf --age=-600_00) can show you what began lately that's still running. Alternately, you could filter for just very old processes you suspect should not exist (like older than a week or $((700*86400)) jiffies) that are also owned by some user or one of the many other filtering criteria, like a kid proc of some server process or so on.

Enforce markAndSweep; Add --limit

Add new --limit time out feature to procs find --action={wait|Wait}.

Also update minimum version of Nim/cligen & add markAndSweep to a build nim.cfg.

Update Nim & cligen deps in nimble

This should be it for a while, update-wise.

Fix version in dot-nimble

Oops. Sorry for the noise!

Cleaner compiles with new warnings

BareExcept & ByteAddress and even Hint[LineTooLong] should no longer fire. Plus a few documentation things.

Nicer Ctrl-C, kill self-avoidance, docs

Also, add nimPreviewSlimSystem compatibility. See RELEASE-NOTES.md or git log for more details.

Add -i to `procs find`; Minor fixes

Basically:

• Add -i flag to procs find to force pattern insensitivity { just by prefixing each pattern with "(?i)" as per lib/impure/nre.nim documentation. Seems to work fine. }
• Make pw less chatty (only ^C not default Nim message), but still exit 130 in case there is some pw patterns && shell construct.
• For >=100% just show integer percentage; 3 significant figures is plenty.
• Ensure data is flushed to stdout before sleeping in differential mode.
• Do not total syscall IO & blockdev IO for %<,%> (too often doubles IO).
• Various updates to sample config and compile-time warning/error fixes.
• Also added release notes for version 0.3.0.