[FEATURE] eigenvalues of selected system in foreground

[pvogt09]

Is your feature request related to a problem? Please describe.
No problem.

Describe the solution you'd like
If a specific eigenvalue for a system is selected with activated cursor function, the eigenvalues of the corresponding system should be colored differently.
After deseletion the initial color should be reset.

Describe alternatives you've considered
None.

Additional context
Implementing this feature might not be feasible in older Matlab versions because it needs to change the calling axis environment while drawing when the cursor function is called and this results in an exception in R2015B.