cpp.staticLibraries and cpp.dynamicLibraries have misleading names

Contrary to what the names suggests, we simply map them to "-l<name>" (unless the full path is given), so the linker uses whatever it can find, e.g. picking up dynamic libs even though the user set cpp.staticLibraries.
We probably should introduce cpp.libraries for the normal case where the user does not care. But what about the existing properties? Should we make them behave like their names suggest, i.e. force that only this type of library is pulled in? Is that even possible with alll toolchains?