First step of the reorganization/cleanup of the LArHV package
The goal of this reorganization is to drop the dependency of the LArHV package on custom reference counting mechanism implemented by GeoModelKernel/RCBase. The latter mechanism is thread-unsafe and it is not really needed for LArHV.
As a first step of this reorganization, only EMBHV* classes have been modified. The EMBHV*ConstLink typedefs have been dropped and the package clients have been migrated to the new interface.