Moving towards block syntax as discussed in #6.

RVTObjectFactory is now a block typedef.
RVTObjectPool, RVTObjectDescription, RVTRelationshipDescription, RVTConfiguration, RVTObjectFactory removed as no longer relevant.
RVTObjectGraphFactory modified to accept an RVTAssembly, which is made up of names and factory blocks.
RVTModule modified to use new block syntax `define:as:`.