SIM: Adding experiment versions and dynamic library loading

[f3sch]

Hi @sawenzel, this a draft based on our discussion to have the possibility to specify the detectors via list. The first commit introduces two new program options, namely detectorVersion version and detectorVersionJSON file and the relevant parsing. Two cases are covered:

1. only detectorVersion specify: then the version is taken from a predefined map with 'official' versions
2. both options are specified: then the custom file is parsed to build the same map as in 1. and the modules are taken from there.

AFAICT this 'works' but I did not test this really thoroughly but running 'o2-sim' with different options seems to do what I want.

The second commit introduces dynamic library loading with a custom dll manager modelled as a singleton. As an example I removed the dependency on 'O2{ITS,TPC,TRK}Simulation' which works as expected and I think can be extended to most other detector simulation libraries. I do not have much experience with this and was more fun experiment :).