[BioPython] Translation method for Seq object

[Peter]

Leighton wrote:
> Peter wrote:
>> I'm still a tiny bit uneasy about the name clash myself... anyone else
>> what to join in the debate?
>
> The problem domain for biological sequences implies a natural definition for
> the application of 'translate' to a DNA/RNA sequence that is the translation
> into protein sequence.  The string.translate() method is not consistent with
> this natural use of the language of the problem domain.
> ...

I thought that was well argued and nicely put.  Of course, someone is
still bound to try calling the 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?  We
currently only expect the codon table argument to be an NCBI genetic
code table name or ID (string or integer).

Earlier I wrote:
>> In Biopython's CVS, the Seq object now has a translate method
>> which does a biological translation.  If anyone comes up with a
>> better proposal before the next release, we can still rename this.
>> Otherwise I will update the Tutorial in CVS shortly...

I have since updated the Tutorial in CVS to use the new transcribe,
back_transcribe and translate methods.  Maybe we should put an updated
"preview" online for comment?

Peter