Adding statistical distributions
Added normal distribution
Added cholesky decomposition, generic matrixSet for dense and sparse matrices, normal distribution sampling
Solved minor problem in matrix set find method
Solved bug at div method for Matrix<T> and SparseMatrix<T>. Solved problems with PDF computation in diagonal normal distribution
Added new parameter to stats.dist.sample method
Removed not needed line in test
Added default constructor of statistical distributions for univariate models
Added test for fast normal distribution constructor
Solved problem with uniform distribution constructor
Added update_params method
Added exponential distribution
Added beta distribution and gamma variate auxiliary function
Minor changes in beta distribution to be coherent with other stats dist.
Added binomial distribution draft and combination class using pascal triangle (as a hash table)
Reimplementation of combinations using a vector, it has less memory overhead
Added binomial distribution, and bernoulli as a shortcut call of B(1,p). Solved memory leak at diagonal normal distribution
Implementing lognormal as derivation of normal
Added first draft of Hamiltonian Monte-Carlo algorithm
Demo for HMC algorithm