Added noisy ellipsoidal function

Rename ellipsoidal.m to ellipsoidalmix in the previous version. Added
noise-free version of ellipsoidal function as ellipsoidal.m. Added a
noisy version of ellipsoidal function as ellipsoidalnoise.m.
Showed the distribution of solution errors

Added a function to show the distribution of solution errors in
cec13_f12 for D=2, M=100, T=1e4.
Increased the number of bins.

The number of bins is increased to 100 from 30.
Automatically determine the value of T

The value of T is automatically determined with the value of M.
Specifically, the formula to determine the value of T is T = 1e6 / M.