patch applied (ghc): Many comments about oclose, plus a fix for Trac #1456

[Simon Peyton Jones]

Fri Jun 29 14:53:34 PDT 2007  simonpj at microsoft.com
  * Many comments about oclose, plus a fix for Trac #1456
  
  There was a rather subtle bug in the way 'oclose' works when
  generalising top-level function definitions.  See
  	Note [Important subtlety in oclose]
  in FunDeps for an explanatoin.
  
  I also tidied up duplication in comments while I was here.
  

    M ./compiler/typecheck/TcSimplify.lhs -46 +18
    M ./compiler/types/FunDeps.lhs -47 +48