Last year, there were several discussions both on this list and the forum about deficiences of reticule implementation.
As of r31973, I have implemented a new TDataPointCrosshairTool, which:
1) Does not require extra properties neither in chart nor in series
2) Should work on Qt and MacOS
3) Allows arbitrary pen for drawing (at the cost of slowdown)
4) Is less confusingly named ;-)

So I have few requests for interested parties:
1) Please test on Linux/Qt and MacOS -- I have tested Windows/Qt only
2) Should I remove TReticuleTool together with all reticule-related properties now,
or wait for another release? Note that built-in properties (ReticulePos, ReticuleMode, UseReticule, OnDrawReticule) were already deprecated
in 0.9.30: http://wiki.freepascal.org/Lazarus_0.9.30_release_notes#TAChart
3) Is the new name really better? If I remove old TReticuleTool, should I rename TDataPointCrosshair tool to TReticuleTool? The old name was invented by original TAChart developer, who is probably French. I actually like the name, but many users expressed confusion as to the meaning of the word "reticule".