Working version with spatial refractive index changes and displacements

- Refractive index values are calculated from spatially varying
pressure, SOS and density.  Using approximation of density found in
Treeby's JAPA paper, where density isn't fully corrected.  He suggested
using it as is, add in the term they ignore, or make a first order
approximation from p=c^2rho.  Currently just ignoring, but something
needs to be verified.

- Displacements are added that follow from velocity using a simple
finite difference scheme (i.e. d = d + u*dt).  Verification needs to be
made as to which time step produces a convergent solution (try halfing
dt until a consistent result is produced).  The issue still remains as
to the correct way to index into the displacements based upon the issue
of MC coordinates and k-Wave coordinates, and how they translate to
getting values from a 'TRealMatrix'.
small change
removing binary files
Deleted previous and added in working directory for previous mentioned changes.
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