Depo ages should be added to past ages plot

[davewhipp]

When using depositional ages from a data file, it would be handy to have them plot on the past ages plot (both panels?) and to title the plot with the misfit value (or have it somewhere on the plot).

[davewhipp]

This probably needs a bit more thought. It seems there could be multiple kinds of depositional ages that could be of interest:

1. Unreset depositional ages where the age could correspond to the time a rock is known to be at the surface as sediment. For these, perhaps it makes sense to compare the age at the time of deposition to the age predicted for a rock sample reaching the surface at the time of deposition.
2. Reset depositional ages where the age would relate to burial and exhumation following deposition. In this case, comparing to the past age might not make that much sense, so it could be more logical to show the age on the plot with the predicted ages at the end of the Tc1D model.

This isn't as easy as earlier thought...