Third release

This is the third release.

In this release I changed the FOKAS files in all folders. These new files are simpler (less lines of code) and produce the right matrix values. I use a .npy files instead of .txt for importing the matrix values, which is supposed to be faster.

The time nodes in Example 3 had to be increased, though, so that stability for the blue line (particle starting at (0, 0.15) was not compromised.