Aragog submodule

[lsoucasse]

We now have a basic version of Aragog implemented within Proteus. This issue lists the next step towards an actual replacement of C-Spider.

• Debug coupled interactions as it seems to misbehave, see here. We could also compare Spider and Aragog on a single run to gain insight on what is going on here @planetmariana.
• Write output profiles to files ExPlanetology/aragog#19
• Redirect aragog logging into proteus
• Use look up tables for thermophysics properties downloaded from the OSF P-T datatables ExPlanetology/aragog#7
• Core cooling model ExPlanetology/aragog#8
• Integration stop conditions ExPlanetology/aragog#21
• Set up a physical integration test #237
• Allow resuming simulation from disk when using aragog #263

[lsoucasse]

Also I realize I did not implement the "attempt" loop as in spider, where tolerance/dt is adjusted when solver fails. Maybe it can help.

[nichollsh]

I have made some progress on the second point. See the plot below. We can think about merging these changes into aragog and PROTEUS once the current aragog-related PR is merged.