Hdtv

- Fix error with errormessage in cal pos nuc (jmayer)
- Test more ROOT versions
- Test Python 3.9

- Fix performance degradation with ROOT 6.20. and higher (fixes 6) (jmayer)
- Fix compatibility with unreleased ROOT Versions 6.19.x (jmayer)
- Note: HDTV will never be compatible with 6.22.00 and 6.22.02
- Fix crash on malformed history files (fixes 19) (opapst)
- Fix compilation without helper functions (jmayer)
- Other small fixes and refactoring (opapst)
- Add horizontal mouse wheel for scrolling (opapst)

- Fix broken root tab-completion
- Triage issue when loading symmetric matrices

- Add better fitting: Integration and Poisson statistics (opapst)
- Add object-oriented background models (ufrimangayer)
- Add exponential background model (ufrimangayer)
- Add spline interpolation background model (ufrimangayer)
- Add light mode (opapst)
- Add magic word `hidden` to select objects (opapst)
- Add keywords and classifiers to setup.py (opapst)
- Add hdtv.app:App() entrypoint instead of script (opapst)
- Add github actions build and tests instead of travis (jmayer, opapst)
- Add GUI-dummy for usage with unit tests (opapst)
- Fix autocomplete of pathes with spaces (opapst)
- Fix hdtv.rootext import order (opapst)
- Fix negative uncertainties from ROOT fits (opapst)
- Move Calibration.hh into separate module (opapst)
- Remove Python2.7 support due to EOL (opapst)
- Remove dead code (opapst)
- Remove usage of global variables and usage of `__main__` namespace (opapst)
- Renamed `%` to `!` to execute batch files for compatibility reasons (opapst)
- Replace code.InteractiveConsole with IPython for Python REPL (opapst)
- Replace readline with prompt_toolkit (opapst)
- Other small fixes

- Release as pypi package (jmayer)
- Use cmake to build extensions (jmayer)
- Bundle libmfile (jmayer)
- Add coverage to unit tests (jmayer, opapst)
- Fix wrong cut axis from mfile matrices (mweinert)
- Other small fixes

- Use uncertainties library (opapst)
- Large overhaul of compiled libraries (nima) (Closes 21)
- Fix efficiency fit and nuclide data (jmayer)
- Other small fixes