Add ability to store an end state and begin a new simulation from it

[Raymond Smith]

If a simulation terminates, there's currently no way to take the final state of that simulation and use it as an input for initial conditions for a new simulation to start from. This would be a useful feature to add.

[Niek Klerk]

I already have some code which (sort of) does this. My code takes the output file from a previous simulation, based on the folder name given in the input-file. And reads in the particle sizes and the concentrations at the end of this simulation. These are then used as starting concentrations for the new simulation. Do you want me to send this code to you?

[Raymond Smith]

Thanks, @niekdeklerk, but I had already almost finished my implementation when I saw this comment. Feel free to look over the continueSim branch to see if I'm missing anything.

[Edwin Khoo]

Fixed in pull request #7.