Initial commit: Developer Tools MVP with visual editor

- Complete React app with 7 developer tools
- JSON Tool with visual structured editor
- Serialize Tool with visual structured editor
- URL, Base64, CSV/JSON, Beautifier, Diff tools
- Responsive navigation with dropdown menu
- Dark/light mode toggle
- Mobile-responsive design with sticky header
- All tools working with copy/paste functionality

node_modules/events/tests/events-list.js

@@ -0,0 +1,28 @@
+'use strict';
+
+var EventEmitter = require('../');
+var assert = require('assert');
+
+var EE = new EventEmitter();
+var m = function() {};
+EE.on('foo', function() {});
+assert.equal(1, EE.eventNames().length);
+assert.equal('foo', EE.eventNames()[0]);
+EE.on('bar', m);
+assert.equal(2, EE.eventNames().length);
+assert.equal('foo', EE.eventNames()[0]);
+assert.equal('bar', EE.eventNames()[1]);
+EE.removeListener('bar', m);
+assert.equal(1, EE.eventNames().length);
+assert.equal('foo', EE.eventNames()[0]);
+
+if (typeof Symbol !== 'undefined') {
+  var s = Symbol('s');
+  EE.on(s, m);
+  assert.equal(2, EE.eventNames().length);
+  assert.equal('foo', EE.eventNames()[0]);
+  assert.equal(s, EE.eventNames()[1]);
+  EE.removeListener(s, m);
+  assert.equal(1, EE.eventNames().length);
+  assert.equal('foo', EE.eventNames()[0]);
+}