Notes on switching to queue points array
pseudocode
comment typo
Partial implementation of trace point queue.
Issues: styles not applied correctly on update (white instead of red); tail end of trace does not appear to be cleared in the display.
Fixed concealGeometry call.
Resolves issues noted in last commit (new point color, and old point tidy)
deleted tmp notes
Simplified updateTrace (no params) and clarified.
UpdateTrace figures out correct preceding point (initialization or update case) itself.
Removed unnecessary date cache