Removed binary constraint from xref.dbprimary_acc (was only used for drosophila, and is no longer required. Was causing problems for Mart)

generate the comma seperate graph file from the percentage file generated by gen_perc_file.pl. One option of acc allowed which will dump accumulated data rather than at each %id cutoff

Added generation of gene descriptions. Previously these were done via a separate script, now they are generated as part of the post-xref-mapping phase.

New implementation uses the same precedence rules for deciding which xref description to assign to a gene as the old script.

In fetch_by_Transcript, updated a throw message so that it says which transcript_id is causing problem