Inconsistent tag usage for file/tree location

The MCASV currently expects a sample to have a valid file if either '.xsp.filepath' or '.init.filepath' tags are found. However TQSample::getTreeLocation does neither consider '.init.filepath' nor '.init.treeName' (only the xsp variants). In order to properly resolve this also some changes to the SampleInitializer(Base) classes are needed in order to set these tags even in a dummy initialization (in case one doesn't care about normalization for MC). Also a warning needs to be issued in this case if there is a treename specified for the initializer which is not fully resolved (i.e. still contains a wildcard).