Insert IMAGE into current buffer at point.
IMAGE is displayed by inserting STRING into the current buffer
with a `display' property whose value is the image. STRING
defaults to a single space if you omit it.
AREA is where to display the image. AREA nil or omitted means
display it in the text area, a value of `left-margin' means
display it in the left marginal area, a value of `right-margin'
means display it in the right marginal area.
SLICE specifies slice of IMAGE to insert. SLICE nil or omitted
means insert whole image. SLICE is a list (X Y WIDTH HEIGHT)
specifying the X and Y positions and WIDTH and HEIGHT of image area
to insert. A float value 0.0 - 1.0 means relative to the width or
height of the image; integer values are taken as pixel values.