Display BUFFER in a window on side SIDE of the selected frame.
ALIST is an association list of symbols and values. The
following symbols can be used:
`side' denotes the side of the existing window where the new
window shall be located. Valid values are `bottom', `right',
`top' and `left'. The default is `bottom'.
`slot' if non-nil, specifies the window slot where to display
BUFFER. A value of zero or nil means use the middle slot on
the specified side. A negative value means use a slot
preceding (that is, above or on the left of) the middle slot.
A positive value means use a slot following (that is, below or
on the right of) the middle slot. The default is zero.