common part of QGD solver

Files
file	extendedFaceStencilCalculateWeights.C
file	extendedFaceStencilFindNeighbours.C
file	extendedFaceStencilScalarGrad.C
file	leastSquaresBase.C
file	leastSquaresBase.H
file	leastSquaresStencil.C
file	leastSquaresStencil.H

Detailed Description

This group contains solvers for calculation of differential operators.