to be done in this version:

• long-named functions removed
• all plotting functions should use separate layers for different parts of a plot
• basic plot types (do not aim too high for this version)
  • barplot (mature)
  • histogram / spine plot (mature)
  • boxplot (mature)
  • par-coords (mature)
  • scatter plot (mature)
  • mosaic plot
  • maps (mature)
  • density plot (mature)
  • missing value plot (mature)
  • time series plot (mature)
  • tour (mature)
• get the interactive legend working
• get documentation of functions and datasets ready

other issues to put to the next stage

• more advanced or merely complementary functionalities (e.g. #62)
• comprehensive pipeline (detailed specification of which part of data changes should fulfill what functionality)
• code optimization; test speed
• vignette
• papers