Minor change in formatting of Gene Association Files (GAF)

We have extended the With/From column (Column 8) of the GAF2 to allow the use of commas as delimiters as well as pipes ("|"). Any GAF files that include this should have "gaf-version: 2.1" in the header, this format is documented here: http://geneontology.org/page/go-annotation-file-gaf-format-21 Other than this there are no other changes.