Recent improvements to MACH2 and MACH3 for fast Z-pinch modeling

Many recent changes in MACH2 have improved the code´s accuracy and speed in Z-pinch simulations. New code diagnostics monitoring energy are also useful in running the code efficiently. The changes to MACH3 are less numerous, though they are more sweeping: MACH3´s grid is now truly three-dimensional and composed of a multiblock structure of arbitrary hexahedral zones; its difference equations have been upgraded to that new mesh. These new capabilities are currently being applied to wire-array Z-pinch problems.