Merge pull request #757 from melissalinkert/pr-679-dev_4_4

Multi-plane flex file with factor and no compression only reads first plane (rebased onto dev_4_4)
merge dev_4_4 -D org -I include -E exclude: PR 673 (Make configuration file suffix configurable)
merge dev_4_4 -D org -I include -E exclude: PR 710 (Data test updates (rebased onto dev_4_4))
merge dev_4_4 -D org -I include -E exclude: PR 746 (CellWorx: ignore thumbnails and missing channel names)