[Biopython] internal function to convert illumina quality scores to phred

[Alan Bergland]

Hi all,

	I am trying to convert some code I've written to use  
FastqGeneralIterator rather than SeqIO.parse.  For the most part, it  
works great and there is a big speed improvement.  However, I need to  
be able to convert the quality scores of 6 characters from the  
Illumina format to phred.  I can't seem to find the function to do  
this.  I'm sure it must exist, and I apologize if documentation for it  
is sitting right there in the tutorial - I can't seem to find it.  Can  
someone point me in the right direction?

Cheers,
Alan