Merge pull request #124 from dmcdougall/sep_impl_vecrealizer

Separate implementation of VectorRealizer
Add separated implementation of VectorRV
Add separated implementation of BetaVectorRV
Add separated implementation of ConcatenatedVectorRV
Add separated implementation of GammaVectorRV
Add separated implementation of GaussianVectorRV
Add separated implementation of GenericVectorRV
Add separated implementation of InverseGammaVectorRV
Add separated implementation of LogNormalVectorRV
Add separated implementation of WignerVectorRV
Add separated implementation of UniformVectorRV
Add make rules for new VectorRV files
Fix up header includes
Fix whitespace in licence
Fix up header includes
Add explicit instantiations