Functionality suggested by Ensembl Genomes, used when building a variation DB.
New flag: start_equals_end which controls the simplified sql for 1bp slice.

(defaults to 200).

Test will fail if run on non-deterministic data storage engines as we have 2 features with the queried for ditag_id

The list will only contain species which have a variation db.

Introduced Utils::IO namespace along with serializer code for GFF3 and human-readable formats. Pre-release, not intended for public use.
Also added Utils::BiotypeMapper that performs ontology mappings.

This enables to have multiple sources of GO terms. The GO terms extracted
from the GFF file will be processed as 'DIRECT' xrefs linked to genes

	formatting

	safe use of @aliases (don't expect registry to make copy of the list)

	quote argument names and values

Add gene_score_threshold (0.125).

(zero by default in the code, but set to 0.125 in the default.conf
configuration file).