MATH-1128
Introducing a "LazyUnweightedEvaluation": the computation of the model
and Jacobian are deferred until one or the other is actually accessed.
Class "LocalMultivariateJacobianFunction" replaces the anonymous class
that was created when calling the "model" method.
The "evaluate" method of "LocalLeastSquaresProblem" instantiates either
"UnweightedEvaluation" or "LazyUnweightedEvaluation", as requested by
the user of the "create" factory method.


git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1603219 13f79535-47bb-0310-9956-ffa450edef68