Fixes #3. We now signal restart condition via null. Since a restart may
need to go back beyond the current model, we now bubble up a null from
the selection simulator. Then wrap the "run simulator" code with a
while(true) and use continue for full restarts.
Fixes #8. Workaround implemented in code.
We really must refactor. This is a workaround. Not a fix really. But i
just can't find the issue. The workaround simply uses -Sc at generation
1 rather than zero, in the case it was set to zero.
Fixed a introduced bug from the last commit.
Fixes #9. Most of the edits are pretty hacky.
Note that we are now going forward with a refactor to make all this a
bit easier.
Fixes #13,Fixes #14,Fixes #11,Fixes #10,Fixes #8,Fixes #4
We still need a workaround for #12. We need to refactor to fix that
properly. Also make the error reports a lot more informative.

Main problems are lifecycle managment of frequency data. However we
cannot deal properly with many -es and -ej options at the same time
instant. This require a refactor.