Increase number of organism-gene entries that can get the encoding gene information line

[nataled]

Follow-up from #161

I've created the aforementioned look-up table. It provides the correct gene name to display on this line for all organism-gene PRO terms that have only a single gene template. I will produce this with every release and place it in the appropriate internal release folder /data/pir/projects/pro/releaseNN. The file is called PRO_orggenes.dat.

Path to current file is /data/pir/projects/pro/release62/PRO_orggenes.dat on hershey
Link to current file is https://hershey.dbi.udel.edu/pir/projects/pro/release62/PRO_orggenes.dat

Optimally, this file would be used to display the gene name for ALL cases of a single gene (multiples are handled differently), obviating the need to search has_gene_template lines or process short labels of parents, etc.

[nataled]

Should we create a property value for this so it appears in the OBO? Could be useful for users too.
@nataled will create a mock-up for this for later discussion.