MATH-1014
"PolynomialCurveFitter" as replacement of "PolynomialFitter". Some tests have
been obsoleted by the refactoring (which hides the optimizer and thus avoids
some potential misuses).


git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1543906 13f79535-47bb-0310-9956-ffa450edef68