Merge additional buttons into existing groups if the group name match…

…es an existing group. See #184

js/bootstrap-markdown.js

@@ -255,7 +255,24 @@
         // Merge the main & additional button groups together
         var allBtnGroups = [];
         if (options.buttons.length > 0) allBtnGroups = allBtnGroups.concat(options.buttons[0]);
-        if (options.additionalButtons.length > 0) allBtnGroups = allBtnGroups.concat(options.additionalButtons[0]);
+        if (options.additionalButtons.length > 0) {
+          // iterate the additional button groups
+          $.each(options.additionalButtons[0], function(idx, buttonGroup){
+
+            // see if the group name of the addional group matches an existing group
+            var matchingGroups = $.grep(allBtnGroups, function(allButtonGroup, allIdx){
+              return allButtonGroup.name === buttonGroup.name;
+            });
+
+            // if it matches add the addional buttons to that group, if not just add it to the all buttons group
+            if(matchingGroups.length > 0) {
+              matchingGroups[0].data = matchingGroups[0].data.concat(buttonGroup.data);
+            } else {              
+              allBtnGroups.push(options.additionalButtons[0][idx]);
+            }
+
+          });
+        } 
 
         // Reduce and/or reorder the button groups
         if (options.reorderButtonGroups.length > 0) {