Merge pull request #463 from melissalinkert/ndpi-npe

NDPI: prevent potential NPE when checking the type
merge develop -D org -I include -E exclude: PR 351 (Add SPW support to FakeReader)
merge develop -D org -I include -E exclude: PR 427 (xsd-fu: Generate sources at build time)
merge develop -D org -I include -E exclude: PR 433 (More .nd2 fixes (rebased onto develop))
merge develop -D org -I include -E exclude: PR 465 (Kryo memoizer)
merge develop -D org -I include -E exclude: PR 467 (Revert "Adding Transform to Image, see #3742")
merge develop -D org -I include -E exclude: PR 468 (scifio: Add BaseMetadata)