Always compute ranking using union. Fixes #310

Author: mikekucera

EnrichmentMapPlugin/src/main/java/org/baderlab/csplugins/enrichmentmap/view/heatmap/HeatMapMainPanel.java

@@ -466,7 +466,7 @@ private void updateSetting_Operator(Operator oper) {
 
 	public void updateSetting_RankOption(RankingOption rankOption) {
 		selectedRankOption = rankOption;
-		List<String> genes = getGenes(getOperator());
+		List<String> genes = unionGenes; // always use all the genes, fixes #310
 
 		HeatMapTableModel tableModel = (HeatMapTableModel) table.getModel();
 		EnrichmentMap map = tableModel.getEnrichmentMap();