Yarp: Methods to check the library version at run time are missing

[drdanz]

Is your feature request related to a problem? Please describe.
There is no way to check the version of the library loaded at runtime.

As described in https://github.com/robotology/QA/issues/325, there is a way to check the version of the library at build time, but no way to know the version of the library loaded at run time.

Describe the solution you'd like
We should add some methods yarp::conf::getVersion(), yarp::conf::getMajorVersion(), etc.

[Nicogene]

And maybe change

std::string Companion::version() {
    return YARP_VERSION;
}

in order to call yarp::conf::getVersion().

[traversaro]

If that method is not inline in the header it should do what @drdanz intended.

[drdanz]

If that method is not inline in the header it should do what @drdanz intended.

Exactly, the only issue is that if we move it in yarp::conf we need to have an actual library (at the moment it's header only).

[drdanz]

Actually I realized that having yarp::conf::getVersion() makes no sense, it would make more sense to have yarp::os::getVersion(), yarp::sig::getVersion(), etc., since we cannot ensure that the version is the same for all the loaded libraries.