Added support for Datatables

Added support for ajax-based server side validation (useful for validation of emails, duplicate usernames, etc.)
User form more or less ready in the basic version (i.e. without permission management)

setup/knex/migrations/20170617123450_create_user_name.js

@@ -0,0 +1,8 @@
+exports.up = function(knex, Promise) {
+    return knex.schema.table('users', table => {
+        table.string('name');
+    })
+};
+
+exports.down = function(knex, Promise) {
+};