Calc window handling

[Chong Yidong]

Hi Jay,

Something broke in the calc window handling recently, at least in my CVS
build.  I don't know whether calc, or Emacs's window management is at
fault.

 emacs -Q
 M-x calc
 q

   => The selected buffer is the Calc buffer, as the only window on the
      frame.  The Calc buffer is supposed to be buried!

Did you change anything in Calc that might have caused this?