Optionally extend cursor tracking to all open MCDs

I would like this:

-- to move the mouse in one chart, and have the crosshairs in all charts in all MCDs track it.

-- to left-click in price-time graph of one chart, and have a scroll-to-that-coordinate message sent to all charts in all MCDs.

These things can be done now only within the current MCD. Because symbol color linking works across all MCDs,it can serve as an example of how to extend cursor tracking.

I'd suggest enabling cross-MCD cursor tracking with a new checkbox in the File/Preferences/Charting property sheet.

Thank you for everything.