021 ncbi fetch

blast: support for remote (ncbi) blast

ncbi_fetch (new): Given list of seqids (gi or accession numbers) fetch their corresponding sequences from ncbi
Actually, looks like I didn't read this carefully enough. The first column of the seqinfo file should contain a sequence name exactly as it appears in the fasta file. 

Also, as a rule, you should use the csv module for all csv output (joining on a comma is not what you want when fields contain commas, and csv will escape as necessary)