zoolog v1.0.1

1. Completed the zoologTaxonomy as a new functionality structuring the taxonomy
   hierarchy for the taxa used in the references.
2. New functions Subtaxonomy, SubtaxonomySet, and GetTaxaIn. All of them taking
   into account the zoologThesaurus$taxon
3. Added new categories in zoologThesaurus$taxon to include also genera,
   in addition to taxa.
4. Integrated the zoologTaxonomy into the function LogRatios. This allows the
   automatic detection of data and reference sharing the same genus, although
   of different taxa.
5. Extended vignettes to incorporate description and illustration of the new
   functionalities.
6. Added several tests for the new functionalities: SubtaxonomySet function and
   LogRatios warning messages and automatic detection of cases with same genus
   but different taxon from reference.
7. Corrected some entries in example dataset, dataValenzuelaLamas2008.
8. Corrected bug on WriteThesaurusSet.
9. Davis’ standard SD, equivalent to Von den Driesch’s DD, has been denoted as
   Davis.SD in order to resolve its incompatibility with Von den Driesch’s SD.
   This has been modified in Davis' reference for sheep and added to the
   thesaurus for measures.
10. Added reference "Steppan" for Bos primigenius. The standards are obtained
    from the same specimen as the reference "Degerbol", but with new and more
    standandard measures.