(int) Mode(window, mode)
This function switches Xic between physical and electrical modes,
or switches sub-windows between the two viewing modes. The first
argument is an integer 0-4, where 0 represents the main window, in
which case the application mode is set, and 1-4 represent the
sub-windows, in which case the viewing mode of that sub-window is set.
The sub-window number is the same number as shown in the window title
bar.
The second argument can be a number or a string. If a number and the
nearest integer is not zero, the mode is electrical, otherwise
physical. If a string that starts with `e' or `E', the
mode is electrical, otherwise physical.
The return value is the new mode setting (0 or 1) or
-1 if the indicated sub-window is not active.
