update the license comment in boot.js

support/boot.js

@@ -7,9 +7,13 @@
 
    ======================================================================
    |
-   | Copyright (c) 2010-2011
+   | Copyright (c) 2010-2013
    | Nicolas Petton <petton.nicolas@gmail.com>
    |
+   | Copyright (c) 2012-2013
+   | The Amber team https://github.com/amber-smalltalk?tab=members
+   | Amber contributors https://github.com/amber-smalltalk/amber/graphs/contributors
+   |
    | Amber is released under the MIT license
    |
    | Permission is hereby granted, free of charge, to any person obtaining