#8 Ask "Save Run" and "Overwrite old data" when starting a sim

[Benjamin Sprague]

Ask the user if they want to save the run data (if it
needs saved) before starting a simulation, so that they
don't run an entire simulation with old settings
because they haven't saved the new settings yet.

Also, ask the user if they are sure that they want to
overwrite old run data if there is run data that
already exists (Maybe only if run data is "valid"), so
that they don't accidentally overwrite old data.