Taxon labels

Adding options for taxon label return format:

- name (cleaned), e.g. "Mus_musculus_sp_ABCD123"
- ott id, e.g. 13572468
- name (cleaned) and ott id, e.g. "Mus_musculus_sp_ABCD123_ott13572468"
- original name "Mus musculus sp. ABCD123"

We should probably provide consistent options in treemachine (except the original name option can perhaps be omitted from treemachine).

@jar398, @mtholder, @josephwb please review/merge.