FoodOn Beta v0.4.8 release

This release brings the replacement of over 1,600 foodon plant and animal species terms with their NCBITaxon equivalents, which now carry all the annotations that the foodon terms had. The separation previously existed because NCBITaxon entities were not thought to necessarily be references to whole organisms, but this attitude is now clear, thus removing the need for corresponding FoodOn entities. A next task will be to ensure as many remaining foodon plant and animal entities can be associated with NCBITaxon as possible; however NCBITaxon isn't a comprehensive taxonomy as it covers only sequenced organisms.