Dclab

- New submodule and classes for managing isoelastics
- New ancillary columns "inert_ratio_raw" and "inert_ratio_cvx"
- Bugfixes:
- Typo when finding contour data files (tdms file format)
- Rrefactoring:
- "features" submodule with basic methods for ancillary columns

- Return event images as gray scale (17)
- Bugfixes:
- Shrink ancillary column size if it exceeds dataset size
- Generate random RTDCBase.identifier (do not use RTDCBase.hash)
to fix problem with identical identifiers for hierarchy children
- Correctly determine contour data files (tdms file format)
- Allow contour data indices larger than uint8

- Add ancillary columns "bright_avg" and "bright_sd" (18, 19)
- Standardize attributes of RTDCBase subclasses (12)
- Refactoring:
- New column names and removal of redundant column identifiers (16)
- Minor improvements towards PEP8 (e.g. 15)
- New class for handling filters (13)
- Bugfixes:
- Hierarchy child computed all ancillary columns of parent upon
checking availability of a column

- Replace OpenCV with imageio
- Add (ancilliary) computation of volume (11)
- Add convenience methods for `Configuration`
- Refactoring (8):
- Separate classes for .tdms, dict-based, and hierarchy datasets
- Introduce "_events" attribute for stored data
- Data columns (including image, trace, contour) are accessed via
keys instead of attributes.
- Make space for new hdf5-based file format
- Introduce ancilliary columns that are computed on-the-fly
(new "_ancilliaries" attribute and "ancilliary_columns.py")

- Add look-up table for elastic modulus (7)
- Add filtering option "remove invalid events" to remove nan/inf
- Support nan and inf in data analysis
- Improve downsampling performance
- Refactor downsampling methods (6)

- Add new histogram-based kernel density estimator (2)
- Refactoring:
- Configuration fully handled by RTDC_DataSet module (5)
- Simplify video export function (4)
- Removed "Plotting" configuration key
- Removed .cfg configuration files