4.0.0

• Added fromArray() factory method to build from PHP array
• build() and quick() factory methods are now deprecated
• Removed poisson() factory method from Matrix and Vector
• Tensor constructors are no longer public
• Modulus results no longer rounded to nearest integer
• Standardized serial representation with extension
• Rename Special interface to Reductions and Algebraic to Unary
• Added sigmoid() to the Unary interface
• Added tanh() to the Trigonometric interface
• Added a Special interface holding softmax()
• Merged the Statistical interface into Reductions and removed Statistical
• SVD::singularValues() and Eigen::eigenvalues() now return a Vector
• Eigendecomposition now returns both real and imaginary parts
• Added padding argument to convolve()