Update documentation with cleaner license declaration

Fix #366

src/utils/Browser.js

@@ -1,12 +1,7 @@
 /**
- * xterm.js: xterm, in the browser
- * Copyright (c) 2016, SourceLair Private Company <www.sourcelair.com> (MIT License)
- */
-
-/**
- * Browser utilities module. This module contains attributes and methods to help with
- * identifying the current browser and platform.
+ * Attributes and methods to help with identifying the current browser and platform.
  * @module xterm/utils/Browser
+ * @license MIT
  */
 
 import { contains } from './Generic.js';

src/utils/Generic.js

@@ -1,12 +1,7 @@
 /**
- * xterm.js: xterm, in the browser
- * Copyright (c) 2016, SourceLair Private Company <www.sourcelair.com> (MIT License)
- */
-
-/**
- * Generic utilities module. This module contains generic methods that can be helpful at
- * different parts of the code base.
+ * Generic utilities module with methods that can be helpful at different parts of the code base.
  * @module xterm/utils/Generic
+ * @license MIT
  */
 
 /**