Minor update v4.5: Statistics window revised

Added

• engine, gui: entire statistical history are saved along with a simulation
• gui/statistics: configurable plot heights
• gui/statistics: collapse specific plots
• gui/browser: statistical history are up/downloaded along with a simulation
• gui/sim view: draw boundaries of the world
• Python script `FindFurtunateTimeline`: constantly monitors populations in a simulation and resort to save points in case of extinction

Changed

• gui/statistics: widgets for real time and time horizon parameter are aligned with the other widgets

Removed

• export statistics function