Added hotkey support to viewerbase

Packages/viewerbase/client/components/viewer/hangingProtocolButtons/hangingProtocolButtons.js

@@ -0,0 +1,11 @@
+Template.hangingProtocolButtons.helpers({
+    'isNextAvailable': function() {
+        var presentationGroup = Session.get('WindowManagerPresentationGroup');
+        var numPresentationGroups = WindowManager.getNumPresentationGroups();
+        return presentationGroup < numPresentationGroups;
+    },
+    'isPreviousAvailable': function() {
+        var presentationGroup = Session.get('WindowManagerPresentationGroup');
+        return presentationGroup > 1;
+    }
+});