Clarify our use of the term phenotype

[cmungall]

Some may use it to describe the complete phenotype of an organism (analogous to genotype)

Our model is also:

• Condition
  • Disease
  • Phenotype

Which does not necessarily conform to others models or terminologies (e.g. OMIM)

Consider renaming Phenotype to PhenotypicFeature (but this would be disruptive, I would vote -1)