/*
   FORMERLY (pre-GRASS4.0):
*  There is a hidden option in this program. `-r`  it creates a reg file that
*  can be used by `digit`.  This is to be used by users who understand
*  the reg file, because the reg file WILL have to be edited for their use.
*  The reg file is a by-product of building the vector file.
*  GRASS4.0:
*    -r option now is for region (was window), NOT reg
*    -x option is now for reg(istration) file. ALSO, this option is no longer
*        hidden, and should be documented for the user.
*/
