Dclab

- fix: `ConfigurationDict.update` did not actually perform the
requested update (does not affect `Configuration.update`)
- enh: also use points_in_polygon from scikit-image to determine
contour levels

- build: import new skimage submodules so that PyInstaller
will find and use them

- enh: improve polygon filter speed by roughly two orders of
magnitude with a cython version taken from scikit-image; there
are only minor differences to the old implementation (top right
point included vs. lower left point included), so this is not
a breaking change (23)

- data: refurbished LUT for linear elastic spheres provided by
Dominic Mokbel and Lucas Wittwer (based on the FEM simulation
results from https://doi.org/10.6084/m9.figshare.12155064.v2);
compared to the old LUT, there is a relative error in Young's
modulus below 0.1 %, which should not cause any breaking changes
- data: updated isoelasticity lines (better spacing): analytical
data was made available by Christoph Herold, numerical data
was interpolated from the new LUT
- scripts: added 'scripts/extract_lut_and_iso.py' for extracting
Young's modulus LUT and isoelastics from FEM simulation data
provided by Lucas Wittwer; this is now the default method for
extracting new LUTs and isoelastics
- scripts: added 'scripts/fem2rtdc.py' for generating in-silico
.rtdc datasets from FEM simulation data provided by Lucas Wittwer
- fix: dclab-verify-dataset failed when the "logs" group was not
present in HDF5 files
- fix: use predefined chunks when writing HDF5 data to avoid
exploding file sizes when writing one event at a time
- fix: create a deep copy of the metadata dictionary when writing
HDF5 data because it leaked to subsequent calls
- ref: changed the way isoelasticity lines and emodulus LUTs
are stored and loaded (e.g. json metadata and a few more sanity
checks)

- feat: enable emodulus extrapolation for `area_um`/`deform` values
outside of the given LUT.

- enh: dclab-verify-dataset now also checks whether the sheath and
sample flow rates add up to the channel flow rate
- ref: Configuration does not anymore load unknown meta data
keyword arguments, but ignores them. This implies that
dclab-verify-dataset will not anymore check them actively.
Instead, any warning issued when opening a file is added
to the list of cues.
- setup: bump nptdms to 0.23.0