Can now support oligonucleotide microarrays other than Affy.
The three affy_* tables are changed to oligo_* tables. New fields are:
  oligo_array.type (currently either AFFY or OLIGO)
  oligo_probe.length
  oligo_probe.description
The existing Affy objects become subclasses of new Oligo objects, but
the API is backwards compatible, so existing pipeline and Web code won't
need changing.

if 'initial_met'

Changed to use info_type & info_text to store projection information rather than rewriting display_label.

Added ability to use Jax-format files for GO terms, where terms are linked to MGI accessions, not UniProt.

Added method to allow the addition of a LIMIT clause depending the database, and methods to convert from date to seconds and from seconds to date due to the different functions in each database system

As the Biomart check only allows one source to map to one type of ensembl entity, there is no point in mapping the Genes and Transcripts as one is moved to the other. So the Gene mapping has been removed