Read cal par

[jenegger]

I added this small macro which allows to have an insight into calibration parameters. Usually they are stored as .root files and the parameter values are usually not readable for the user. This minimal macro requests the calibration parameter file (either .par or .root file) and gives as output (either on terminal or redirected on a textfile) all the calibration parameter values stored in the calibration parameter file.

[klenze]

It should be noted that this concerns the CALIFA per-crystal energy calibration parameters.

I think that this macro will be very helpful as a reference to access rtdb parameters in a minimal way. (Note that this is not quite trivial: order matters. First rtdb->getContainer, then rtdb->initContainers, then access the container contents. Any other order will result in just reading the default data instead of the data from the file.)

The maintainers will probably ask you to squash the commits before merging the PR.

[kresan]

@jenegger please rebase and squash the commits