Body-fitted coordinates

1. top of file /phoenics/d_earth/d_opt/d_bfc/gxbfgr.for
2. subroutine GXBFC enables cartesian velocities to be set at boundaries
3. subroutine BFCFX: a utility used by gxbfc
4. subroutine GXBFGR exemplifies the creation of a moving grid
5. subroutine SECRNS: a utility for setting corner coordinates