FDS Source: Pad arrays for RHO, ZZ and TMP

[mcgratta]

This PR makes the arrays for ZZ, RHO, and TMP one cell wider in all directions, yielding 2 ghost cells rather than 1. The purpose is to more easily compute flux limiters at mesh boundaries. This PR does not change the functionality of the code. It does the following:

1. Expand the arrays, RHO, ZZ, etc.
2. Populate the second ghost cell values of RHO, ZZ and TMP
3. Establish a comparable working array called WORK_PAD
4. Use the new work array to send the scalar array to GET_SCALAR_FACE_VALUE
   Things to do
5. Expand the bounds in calls to GET_SCALAR_FACE_VALUE from, say, (1:IBM1) to (0:IBAR)
6. Remove any unneeded calls at mesh boundaries