added an entropy fix to the MHD Roe solver that causes oscillations in steady states, but prevents the negative pressure situation.  TODO a better one.  started to turn the Euler HLL solver into one that solves in the x-normal-only.  removed unnecessary negatives from the Euler Roe solver when rotating into and out of the surface normal.  Plan to get HLL working in x-axis, maybe add HLLC, maybe add flux limiter, then use this as a degenerate case when we get negative pressures in MHD Roe