Precedence issues in structural input

• If the ``server'' option is active, it takes precedence over everything (it will overwrite all other input with the information it gets from the FIFO file).

• If MD.UseSaveXV is active, it takes precedence over the options below.

• If UseStructFile (or MD.UseStructFile) is active, it takes precedence over the options below.

• For atomic coordinates, the traditional and Zmatrix formats in the fdf file are mutually exclusive. If MD.UseSaveZM is active, the contents of the ZM file, if found, take precedence over the Zmatrix information in the fdf file.