To systemtest Relax_disp.test_task_7882_monte_carlo_std_residual(), added tests for creation of Monte-Carlo data
by different methods.
Task #7882 (https://gna.org/task/?7882): Implement Monte-Carlo simulation, where errors are generated with width of standard deviation or residuals.): Implement Monte-Carlo simulation, where errors are generated with width of standard deviation or residuals.
