ZeroR is broken

[nirvdrum]

ZeroR chooses the first class value it comes across, not the most frequently accessed one. The test suite is a bit flawed in that the first class value also happens to be the most frequently accessed one.

The core problem is that no frequency is ever calculate so every class value looks like it has a frequency of 1.

I've fixed the problem on this branch:
http://github.com/nirvdrum/ai4r/tree/fix_zeror

With this commit:
ca6a404

[SergioFierens]

Patched.
Took a while, but I finally pulled it :)

[nirvdrum]

Heh. No worries. I guess I could have issued a pull request. This predates all the fun stuff GitHub has added in the past three years.