Added solveInPlace to HessMatrixExpressions
Added solveInPlace to HessMatrixExpressions

This new solve routine solves upper Hessenberg systems using Gauss
elimination with row pivoting. This method is to be prefered over
factorLU and solveLU for system which are not known a-priori to
be diagonally dominate.

bsilbaugh/NumLib,bsilbaugh/NumLib,bsilbaugh/NumLib,bsilbaugh/NumLib