Miscellaneous functions for data cleaning and data analysis of educational assessments. Includes functions for descriptive
analyses, character vector manipulations and weighted statistics. Mainly a lightweight dependency for the packages 'eatRep',
'eatGADS', 'eatPrep' and 'eatModel' (which will be subsequently submitted to 'CRAN').
The function for defining (weighted) contrasts in weighted effect coding refers to
te Grotenhuis et al. (2017)