Things missing:

	*** Add support for MethodInfos ** and the nullable stuff, I believe
	we have to pull the values before calling the various
	MethodINfos in BinaryExpression, need to write test

       Coalesce's conversion, what is this used for?

       Constant generation of objects, how are those Constants in the first place?

       Try: 
       	    OrElse (Constant (new Boo(), new Boo ()))

Tests missing:

	Must write tests for all the codepaths currently in
	BinaryExpression.Emit (specially the XXXChecked variants as
	those so far have shown most of the problems).


	Write tests for stuff using MethodInfos (the various
	BinaryExpressions using MEthodInfos have been barely tested).   

	Write more tests using nullables, currently we are short on
	them, and they are not extensively tested.

	Missing:
		Add, Subtract, Multiply, Divide, Modulo, <<, >> And, Or, Xor

		MultiplyChecked, DivideChecked, 

		case ExpressionType.OrElse:
		case ExpressionType.AndAlso: