Saved configs not the same as input configs

[jack89roberts]

In the configs saved with the models we expand out everything (so e.g. the data config name is replaced with the actual contents of the data config). Either:

• Make it so the experiment config class can create a config from either format
• Make the saved format the same as the input format

And:

• Change the eval scripts (e.g. all_eval.py) to use the experiment config class rather than using the output configs as a dictionary