wkt:

Renamed the second in each of the unimplemented __dump functions
(to match the implemented ones).
wkt:

Implemented `__dump_multipoint`.
wkt:

Implemented `__load_multipoint`.
tests/wkt_test:

PEP8 style fixes.
tests/wkt_test:

Added a couple of test cases for multipoint wkt loading.

I still need to add 3d and 4d test cases.
tests/wkt_test:

Added 2d, 3d, and 4d test cases for multipoint wkt dumps.