checked int-int conversions

[John W. Eaton]

On 30-Jul-2008, Jaroslav Hajek wrote:

| A good idea - I forgot to check the Matlab counterparts. Should I
| resubmit the patch (given that this is, as I understand, a trivial
| change)?

I've already checked it in to my archive, so I'll fix it up.  It
should be pushed to the public archive soon.

I'm also eliminating the trunc_flag thing in favor of passing an
additional argument by reference to the constructor.  To me, the extra
argument seems better than having a static data member for this purpose.

jwe