allow subsets to contain sets themselves

[aebrahim]

If the number of arguments in subsets is the number of sets (i.e. 2 for venn2 or 3 for venn3), then assume they are sets and calculate the intersection areas using set operations.

[konstantint]

Thanks, this is certainly a feature I have been planning to add for a long time now, however I'd like to have it in a separate "utility" function (I find the idea of crazy parameter overloading like that somewhat dangerous, who knows what other possible usages one may come up with later, it also makes testing inconveniently hard).

I'll try to find time in the next week-or-two to add this and a couple of other things.

[konstantint]

... or, well, let it be this way. It does look very convenient without a separate function.

[aebrahim]

Convenience is always a compelling argument :)