Introducing Multi-Condition version of CVC-MUSCIMA

This release features a multi-condition version of the CVC-MUSCIMA that consists of files from the Staff-Removal and the Writer-Identification datasets. The images from both datasets have been aligned to have exactly the same dimensions and overlap as good as possible. The dataset contains a total of 10000 png files with 10 different conditions: grayscale, binary, interrupted, kanungo, staffline-thickness-variation-v1, staffline-thickness-variation-v2, staffline-y-variation-v1, staffline-y-variation-v2, typeset-emulation and whitespeckles.
Note that these augmented version are just taken from the Staff-Removal dataset and inverted to be consistent with all other images black on white background.