An optional parameter has been added to extendTraces and prependTraces that specifies whether the graph should be redrawn after a new group of traces has been appended or prepended, as the case may be.  This can be useful when the time to redraw cannot keep up with the frequency in which new data arrives, or when data arrives so fast that updating the graph with each trace addition is distracting.  Importantly, this change is backward compatible with any prior version, as the optional redraw parameter defaults to true, thus, unless explicitly set to false, graphs will continue to be redrawn after each trace addition.

Add redrawMinimumInterval parameter to config for use with extendTraces/prependTraces.  Fully backwards compatible as default is zero.

Revert previous changes and attempt to implement suggestion of @alexcjohnson to use throttle functionality for extendTraces/prependTraces minimum redraw interval.

Update to reflect change in approach suggested by @alexcjohnson.