Overhaul of PMLs and introduction of new, optional MRIPML formulation.

tests/models_pmls/pml_off.in

@@ -0,0 +1,10 @@
+#title: PML test none
+#domain: 0.100 0.100 0.100
+#dx_dy_dz: 0.001 0.001 0.001
+#time_window: 3e-9
+
+#waveform: gaussiandot 1 1e9 myWave
+#hertzian_dipole: z 0.050 0.050 0.050 myWave
+#rx: 0.070 0.070 0.070
+
+#pml_cells: 0