Add "Restart" button on cTrader Desktop

Just add a simple “Restart” button to the platform to solve the issues where it froze after being used for a long time with backtesting, optimization, or multiple charts. 

This will be extremely useful for using the platform for a longer time without needing to close and re-open it constantly.

After some time spent backtesting and optimizing algorithms, the platform becomes very slow and unresponsive. Restarting the platform automatically solves this issue.

In any case, the platform needs to be restarted after some time when using it for long periods, so this button will only facilitate a process that has to be done anyways.