Added noisy sphere test function

Added sphere function with additional noise, which is zero mean Gaussian
distribution N(0, 1).
Rename sphere.m to spheremix.m
Added real parameter sphere test function
Reduced standard deviation of Gaussian noise

Reduced standard deviation of Gaussian noise to 0.01 from 1.0 in the
noisy sphere function.
Enhanced noise handling in Pro JADE/eig

Increase the speed of increasing samples. Used mean of candidate
solutions instead of the best solution as the final result.
Tested Pro JADE/eig on the noisy sphere function

Resolved negative function values problem on semilogy function. Show
loglog instead of semilogy for standard deviation of function values and
solutions.
Let cmaesshell.m support noise handling
Let SDE/mean/2/eig support noise optimization
Revert "Reduced standard deviation of Gaussian noise"

This reverts commit df6e60741a1af20f4a97c78dfbd1241b6dcb9c4c.
Parameterize the sample factor in Pro JADE/eig
Added an optimization for noise optimization

Added Pro JADE/eig optimization for noisy real-parameter optimization.
Used fminbnd to optimize Pro JADE/eig
Added a function to test noise optimization

Added a new MATLAB function to test the performance of a solver for a
specified test function with objective function evaluation noise over 50
independent runs.
Show loglog instead of plot for samples
Set TolX to 0.0001

Set tolerant X to 0.0001 from 0.0.
Optimized SampleFactor parameter

SampleFactor parameter is optimized, in which the optimal value is
1.25668 by fminbnd. However, please note that the optimization is
essentially noisy. In other words, the optimal value is not the true
optimum. It approximates the true optimum. That's all.