Fix customChartColors() to only set one 'mousemove' handler
Fix customChartColors() to only set one 'mousemove' handler

Rather than twice a second attaching a new 'mousemove' event handler,
do all the other color-overwriting twice a second but just attach one
'mousemove' event handler when first configuring the custom chart
colors.

Factor preparatory data massaging needed by both mousemove handler and
drawColors() into its own function called by each.

mode/alamode,leqilong/alamode