inconsistent approximate counting implementation

[henrikac]

The Approximate Counting algorithm currently has four implementations and four different ways of how to act on the result of abs((avg - n_items) / n_items) < threshold.

Julia	What it does
Julia	Returns true or false
Python	prints "passed" if the condition is true
C++	returns "pass" if the condition is true, otherwise "fail"
C	aborts program execution

[leios]

I have been wrapping all the Julia code into @testsets do get a pass and fail of each test; however, this raises a good point. For consistency with other languages, maybe we should adopt something less language specific.

[henrikac]

For consistency with other languages, maybe we should adopt something less language specific

A standardization of the output/behaviour as a minimum would be good idea (imo), otherwise it might end up like #857 when more languages get implemented.