Improved safety for param_t structures

[marco-palmiotto]

Hi, while I am finishing to improve the compare branch (to avoid the warnings), I noticed two important improvements that can be done for the param_t type and its use. In particular

1. calling par->getName() instead of par->name in the print function. This allows to set name as private in InintSanitizer
2. making print a const method, to allow for calling it in scopes where the param_t variable is qualified as const

I can do them myself in the compare branch, however I could not find the correct source files to modify them.