ontofetch.py not returning all contents under specified root

[ddooley]

Try running ontofetch.py with the following arguments:

http://purl.obolibrary.org/obo/foodon.owl -r http://purl.obolibrary.org/obo/BFO_0000001

Observe "food material", and some of its children (e.g., seafood product), were not fetched in the resulting output.

Now try:

http://purl.obolibrary.org/obo/foodon.owl -r http://purl.obolibrary.org/obo/FOODON_00002403.

Observe seafood product was now fetched, but other children (e.g., baked beans (dish) were not.