Review: Foam::distributionModels

• Some member models could be refactored by using C++11 #include <random>, e.g.:
  • Foam::distributionModels::RosinRammler -> std::weibull_distribution
  • Foam::distributionModels::exponential -> std::exponential_distribution (although the latter does not provide any mechanism to min/max the support)
  • Foam::distributionModels::uniform -> std::uniform_real_distribution
  • Foam::distributionModels::normal -> std::normal_distribution
• Namespace content could be chucked outside the Lagrangian context to enable users/developers to generate random variates sampled from a chosen distribution. Maybe into Random.H?