Added test functions defined in CLOP paper

Seven test functions of CLOP paper are added to this project. They are:
LOG, FLAT, POWER, ANGLE, STEP, ROSENBROCK, and CORRELATED.
Illustrated CLOP test functions

Added a function to illustrate the CLOP test functions, using the newly
added functionsampler.m, plotfunction.m, and setdefoptions.m, which are
helpful utility functions.
Let CLOP functions support high dimension

CLOP functions can now evaluate two or higher dimensional solutions.
Added 2-dimensional LOG function to illustration
Added three noise-free CLOP test functions

Added noise-free LOG, ROSENBROCK, and CORRELATED functions in CLOP
paper.
Illustrated noise-free functions in CLOP
Added known minimizer to comments of functions

Added known minimizer to the comments of three CLOP test functions.
Added a modified UH-CMA-ES

This modified UH-CMA-ES increases samples to average the noise for each
generation.