uint64 documentation

[Rik]

Jaroslav,

I'm updating the documentation for the 3.4 release.  This section from
4.4.1 on Integer Arithmetic seems to be out-of-date and does not reflect
the addition of the int64 and uint64 types.  Is that right?

"The arithmetic operations on integers are performed by casting the integer
values to double precision values, performing the operation, and then
re-casting the values back to the original integer type. As the double
precision type of Octave is only capable of representing integers with up
to 53 bits of precision, it is not possible to perform arithmetic
with 64 bit integer types."

--Rik