Dclab

- fix: integer overflow in downsample_grid
- fix: removed unnecessary computation of hierarchy filter instance
- enh: cythonize downsample_grid (~10x speed-up)
- enh: got rid of for-loop in map_indices_parent2child (~100x speed-up)
- enh: slight improvement of managing manual indices in hierarchy children
- enh: added dtype properties for contour and trace events
- enh: ensure all feature data objects have the dtype property
- enh: globally use chunk sizes of ~1MiB when writing HDF5 data (217)
(minor speedup since previously a chunk size of 100 events was used
for images and scalar features were written in one big chunk)
- enh: favor array operations in `yield_filtered_array_stacks` (~4x speed-up)
- enh: increase verbosity for unreachable remote basin features
- ref: implement `__array__` methods for hierarchy event classes
- ref: implement `__array__` method for `H5MaskEvent`
- ref: new submodule for hierarchy format

- fix: regression missing check for basin availability

- enh: perform basin availability checks in daemon thread

- enh: priority-based basin sorting (file over remote, http over dcor)

- feat: allow nested basins
- feat: implement DCOR basins
- fix: make sure basins are always closed on context exit (238)
- fix: failed to load basin data when port was specified in location
- enh: requests session pooling for fmt_http and fmt_dcor
- enh: implement context manager for RTDCBase
- enh: be forwards-compatible and ignore unsupported basin formats
- ref: new http_utils submodule for managing HTTP connections

- test: tested rtdc_dataset.config.Configuration is pickable (190)
- enh: add dcnum pipeline identifier metadata constants