Add sorted take optimizations

closes #880

Should be good enough, I think.
@reconditesea sure, I can make a constant (but I have to add {}, which you know I hate. :)

@avibryant can you suggest how to do your suggestion? I agree that it sucks to have some hard coded constant. But only in the case of sorting did I work this out. What does the method look like? Where it the hierarchy is it?