Misas

- Re-write internal function to use pillow instead of fastai (version 1)

Changes:
- more convenient plotting of evaluation series `plot_eval_series`
- different `eval_function`s for `eval_generic_series`: `recall_by_component`, `precision_by_component`
- documentation how to use different evaluation functions and define custom ones
- add functions to easily create and plot confusion matrices

- Fix transparency of background class in masks (`cmap` parameter)
- Fix class numbers with `vmax` parameter
- Fix `zoom` and `crop` functions for images of different sizes (`finalSize` parameter)
- Add compatibility to more recent `torchio` versions
- Add multi class pathology segmentation example
- Update documentation
- Bug fixes