Remove some unused GO terms, one of which is obsolete in GO.

[balhoff]

Fixes #530.

I deleted 'synapse part' and its subclasses 'presynaptic membrane' and 'postsynaptic membrane'. None of them had any usages in axioms. I didn't see any automated way to regenerate the go_cc_import.owl.

[balhoff]

I looked at usages in ro-edit.owl within Protege. Shouldn't that be a superset of ro-base?

[matentzn]

Yes it is! Thanks.

[balhoff]

Wait—now I do see where this is "used":

synapsed_by_via_type_III_bouton expand expression to "BFO_0000051 some (GO_0042734 that BFO_0000050 some (GO_0045202 that BFO_0000051 some (GO_0097467 that BFO_0000051 some GO_0045211 that BFO_0000050 some ?Y)))"

[balhoff]

I changed to draft to look at this a little further before merging.

[cmungall]

any further thoughts @balhoff ?