Parameter handling

In addition saw and sat, and now Ratfor90, simplify parameter handling. Ratfor90 calls an essential SEPlib initialization routine initpar(), organizes the self-doc, and allows for various parameter handling keywords (from history, from par, from either, from aux, to aux, to history). For example, the line:

from either: integer n1,n2:ns,n3:nv=1

is translated into the much more verbose:

 if (0==fetch('n1','d',n1)) then
    call seperr('Could not obtain n1 from either')
  end if
  if (0/=putch('From either: n1','d',n1)) then
    call seperr('trouble writing n1 to history file')
  end if
  if (0==fetch('n2','d',ns)) then
    call seperr('Could not obtain n2 from either')
  end if
  if (0/=putch('From either: n2','d',ns)) then
    call seperr('trouble writing n2 to history file')
  end if
  if (0==fetch('n3','d',nv)) then
    nv=1
  end if
  if (0/=putch('From either: n3','d',nv)) then
    call seperr('trouble writing n3 to history file')
  end if