Draft LW2 spec

[Brian Goetz]

>
> There are a few "design discussion" blocks that identify areas that 
> may evolve further (in LW3, say) or where the design choices we've 
> settled on aren't necessarily essential.

Here's a few more:

  - The ACC_INLINE bit may well go away if we settle on a RefObject / 
ValObject hierarchy; then a class is an inline class iff it extends 
ValObject.  (In the current formulation, I think you want to add in 
INLINE -> !INTERFACE too.)
  - NullFreeClassType may prefer to be called something else; this is 
the "new contract" story John is working on.  And some "new contract" 
types may be nullable as well, if we go forward with the null-default story.