[MLton] MLton library project

[Stephen Weeks]

> My thoughts are that `MLton-LICENSE' should be refactored to two
> pieces:
>   - the copyright (Cejtin, Fluet, Jagannathan, Weeks, NEC)
>   - the license and disclaimer (without hard coded references to
>     owners)

Makes sense.  We definitely did not intend for others to assign
copyright.  I've tweaked doc/license/MLton-LICENSE (and hence
http://mlton.org/License).  The idea now is that the copyright notice
lives in each source file (and may be different depending on who
contributed the code) while every source file points to MLton-LICENSE
with the following two lines:

 * MLton is released under a BSD-style license.
 * See the file MLton-LICENSE for details.

Let me know if that works.