[Developers] Deleting the "Chemist" type

[Jeff Prucher]

There's been a suggestion to delete the the type /chemistry/chemist, and
just use the "profession" property of the Person type to assert that
someone's a chemist (since the type has no properties).  There are only a
couple dozen instances of this type, so I'm guessing that nobody is using it
much, but speak up if removing this type will affect any of your queries or
views.

Jeff