enable adding more than one assay or environment term to phenotype

[pfey03]

In the new curation, we should be able to use >1 environment or assay term with each phenotype. And we need AND and OR statements.

For environment, a couple examples:

• 'during starvation' AND 'at high cell density'
• 'on filter' OR 'on 'non-nutrient agar'

Thanks! Petra & Bob