Finished random number generator refactor. Solver managers for
monte carlo, sequential MC, and MCSA are now templated on a
random number generator type. For now, this will work only with
c++11 generators and potentially boost generators. A more explicit
traits class will enable the use of other generators including
those specified by the user. This extra template parameter is
hidden by the SolverManager interface and therefore is not
accessible from the MCLS::SolverFactory as well as Thyra or
Stratimikos. In these cases the template parameter defaults
to std::mt19937.