Implicit discretization

Topics
	Numbering and Ordering Cartesian neighbors
	Base function to number Cartesian neighbors.
	Cell scalar
	Implicit discretization of a scalar equation defined on cells.
	Face vector
	Implicit discretization of schemes and linear system creation of a vectorial equation defined on faces.

Detailed Description

The directory is organized as follow:

• cell_scalar directory contains routines associated to the discetization of PDE defined on cells
• face_vector directory contains routines associated to the discetization of PDE defined on faces
• ijk_vectorization routine helps to linearized the 3D array for the creation of the linear system
• generate_stencil module numbers and orders Cartesian neighbors.
• enumeration, fields and variables files associated to the implicit discretiation

  Todo:

  MCO update the above documentation