Dclab

- enh: speed-up contour computation by a factor of three
(volume is computed by factor of two faster)

- enh: make IntegrityChecker class available on top level module

- BREAKING CHANGE: The volume feature in all previous versions was
overestimated by about 2µm³. Please re-run your analysis pipeline.
- fix: volume was computed incorrectly (141)

- setup: bump h5py version to 3.0 (issue with integer chunk argument)

- feat: introduce new RTDCWriter class (144)
- fix: in some rare cases, an empty .rtdc file could be generated
when splitting an .rtdc file via the CLI dclab-split
- fix: user-defined metadata were not copied with CLI repack
- fix: support exporting non-scalar plugin features to HDF5 (143)
- enh: implement consistent `.shape` property for contour data
(partially 117)
- enh: improve export speed of contour data
- enh: improve export speed if data filtering is disabled
- ref: disable `time_offset` of internal `export.hdf5_append` function
- ref: deprecate write_hdf5.write function
- ref: deprecate export.hdf5_autocomplete_config function
- ref: deprecate export.hdf5_append function

- fix: write logs to fixed-length strings in HDF5 files (HDF5 never
supported variable length string datasets with fletcher32 or compression
filters)
- fix: non-scalar features that are not defined in dclab were silently
ignored upon export; temporarily raise a ValueError instead (143)
- setup: release pinning of h5py