ILU Jacobi Iterative Triangular Solve Implementation

[PaulMullowney]

Jacobi iterative solver for ILU smoother/preconditioner implemented on CPU/GPU currently for Nvidia only since we don't have AMD ILU factorization yet. This will occur in the next PR. This works with ILU0, ILU(k), and ILUT. For Schur compliment-based solves, we force tri_solve==1 during the setup and not allow iterative triangular solve during the solve phase. This will be implemented in a subsequent PR. When iterative tri solve is chosen for ILU0, ILU(k), an ILUT, one doesn't need to call solve analysis for the L and U factors. This yields a nontrivial performance gain.