Remove duplicate models (across Taxa) in existing publications

[brycefrank]

This is an extremely low priority item, but it would be proper to remove duplicate models from publications now that the Taxa structure exists. For example

models/parameters/hst_fvs_2008_2.csv

Lines 15 to 16 in ddf1bc0

	KP,5.188,-13.801,Pinaceae,Pinus,attenuata
	LL,5.188,-13.801,Pinaceae,Larix,lyallii

can be grouped into a taxa containing two taxons.

We also should make a standard procedure for structuring a parameter csv for this purpose, and any modifications needed to aggregate_taxa to accommodate this grouping structure. Maybe taxa_group_id column, which is discarded?