Moving the namespace and some functions from user-management to user package

Packages/ohif-user/client/lib/logout.js

@@ -0,0 +1,11 @@
+import { Meteor } from 'meteor/meteor';
+import { OHIF } from 'meteor/ohif:core';
+
+OHIF.user.logout = () => Meteor.logout(error => {
+    if (error) {
+        OHIF.ui.showDialog('dialogInfo', {
+            title: 'Error',
+            message: error.reason
+        });
+    }
+});