Some refactoring in preparation for upcoming package restructuring.

Temporarily removed filtering out of low-identity mappings (to allow comparison with current human SwissProt mappings).

HUGO parser. Ref seq Accesssion check still needs to be resolved as hugo has NO version numbers whereas at the moment these are stored when parsing refseq

set_disconnect_when_inactive method added which will disconnect ALL DBConnections and set the flag for disconnect_when_inactive to 1

ftp://ftp.informatics.jax.org/pub/reports/MRK_SwissProt_LocusLink.rpt  no longer needed to be down loaded for the MGI data to be loaded as the list of valid accessions is now obtained from the database. This alos makes the doen loading easier as before we had to download two files for one parser.

MRK_SwissProt_TrEMBL.rpt is the only file needed here as a list of valid accession is obtained from the database itself. This is the first draft of the MGD/MGI data also known as markersymbol in the ensembl code. Note the data can also be gained from parsing the Swissprot files but this data maybe older.