add and update license

go/glicko2.go

@@ -1,3 +1,27 @@
+//
+//
+// Copyright (c) 2013 Stephen Waits
+// 
+// This software is provided 'as-is', without any express or implied warranty. In
+// no event will the authors be held liable for any damages arising from the use
+// of this software.
+// 
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it freely,
+// subject to the following restrictions:
+// 
+// 1. The origin of this software must not be misrepresented; you must not claim
+//    that you wrote the original software. If you use this software in a
+//    product, an acknowledgment in the product documentation would be
+//    appreciated but is not required.
+// 
+// 2. Altered source versions must be plainly marked as such, and must not be
+//    misrepresented as being the original software.
+// 
+// 3. This notice may not be removed or altered from any source distribution.
+//
+//
+//
 // Glicko-2 Rating calculator package.
 //
 // This package implements the Glicko-2 rating system algorithm written by