Allow to run parallel and batch experiments with different parameters for analysis

[yaelbh]

What is the expected behavior?

Suppose that I have two T1 experiments, on different qubits, which I run in a parallel experiment. I'd like to analyze them with different parameters, for example different p0. This is impossible.

This is a general issue with the design, related to all the experiments, T1 is only an example.

[yaelbh]

This can perhaps be solved by using the _experiment data member of the ExperimentData class.

[yaelbh]

I'll work about it soon. It will be easier to integrate with the result db if the code on our side is cleaner.

[chriseclectic]

Implemented in #39