[BioPython] Translation method for Seq object

[Peter]

On 20th Oct I wrote:
> Of course, someone is still bound to try calling the [Seq object's]
> translate method with a string mapping.  Maybe we should add a
> bit of defensive code to check the table argument, and print a
> helpful error message when this happens?

I've just added that in CVS, if the table argument is a 256 character
string then a ValueError is raised suggesting using
str(my_seq).translate(...) instead.

Peter