TODO

Known Bugs:
* having an expression in the category names prints, but is left aligned with multiple lines instead of centred

Improvements to make:
* COMMENT COMMENT COMMENT
* Structure the various functions so that they have identical parameter structures where possible
* Move away from scalars for areas and convert everything, where possible, to vectors and lists
* Add functionality into the venn.diagram function so that it will save in a specific file type given an appropriate file extension (BoutrosLab.plotting.general has a good solution)
* There may be a non-unique solution to the triple-Venn scaling problem as implemented in Vennerable (https://r-forge.r-project.org/projects/vennerable/)
* Weirdness in venn.diagram help in the PDF version with lack of wrapping in the parameter-table