9.2.8: Add informative note on IEEE Decimal?

For the existing Standard 11.1.7 the Annotated Standard includes two annotations: the first references the CLI committee's discussion and the decision to allow, but not require, CLI implementations to use IEEE Decimal; the second, written by Mike Cowlishaw, details how an implementation might support the old MS format and the IEEE format automatically.

The CLI Standard itself includes the following:

> Note: In Version 1 of this standard, the representation of System.Decimal was well-defined, as follows.
> ...
> In order to allow alternate representations (such as in the update to the IEC floating-point standard, IEC-60559, currently in preparation), the representation has been made unspecified.

The question is whether this allowance in the CLI should be referenced directly in the C# Standard, say as an informative note.

The existing text of 10.2.8 goes to some length to describe the abstract representation and _minimum_ (emphasis added) range. If that is deemed explicit enough then no note is _required_, if not then one might be indicated.