Add Crosshairs tool to OHIF Viewer / Standalone Viewer

OHIFViewer/client/components/toolbarSection/toolbarSection.js

@@ -62,6 +62,13 @@ Template.toolbarSection.helpers({
     toolbarButtons() {
         const extraTools = [];
 
+        extraTools.push({
+            id: 'crosshairs',
+            title: 'Crosshairs',
+            classes: 'imageViewerTool',
+            iconClasses: 'fa fa-crosshairs'
+        });
+
         extraTools.push({
             id: 'stackScroll',
             title: 'Stack Scroll',