Committed to the wrong branch! Ouch. Fortunaly only a one line change.

Revert "Added names div id values to this.droppable_divs (lines 2-5 - RmodulesView.js) to cover previously missing div types (especially those from ForestPlot!), in particular: divReferenceVariable and divStratificationVariable. Fixes drop-and-drag error, TMART-85. Problems remain with ForestPlot. See TMART-270 for additional errors."

This reverts commit 725a9109672cd8b02a3bb97e798e76848f4b47b8.