`dataset_id` field in `taxonomic_updates` table is incorrect

[ehwenk]

In the taxonomic updates table, the dataset_id field indicates all datasets which have a given original_name. However in instances, where the same original_name becomes different aligned_names (i.e. all the genus sp. taxa that have the dataset_id added to them), each instance of the original_name lists all dataset_id's. For instance:

Angevin_2011 Lunt_2012 Purdie_1976 | Poa sp. | Poa sp. [Angevin_2011] | genus | NA Angevin_2011 Lunt_2012 Purdie_1976 | Poa sp. | Poa sp. [Lunt_2012] | genus | NA Angevin_2011 Lunt_2012 Purdie_1976 | Poa sp. | Poa sp. [Purdie_1976] | genus | NA

[ehwenk]

closed with commit a7e4730