This adds some new features like recording of nick chains, time stamps
of the summary period, mode revolving and optional display of rejoins.
The features can be enabled with /set
* make it easier to change the displayed text
* try harder to not delete the wrong line when /ignore or other
line-removing code is in effect
* add trackbar awareness
* correct logic flaw when re-adding joins
* rewrite /quit scanning logic
* move work to print text handler