Correct omission of license header in each source file.

This is the initial release of Shiva. It contains initial implantation for:

• Spacing classes for defining discretization of a line for Equal, Gauss-Legendre, and Gauss-Lobatto spacing.
• Quadrature classes to define quadrature weights.
• Lagrange Basis and BasisProduct
• Base geometries (NCube, NSimplex) and the InterpolatedShape which applies an interpolation on the shape.
• Transformations of base geometries. Currently there are LinearTransform, Scaling, and UniformScaling.
• A parent element implementation to perform value and gradient calculations.