Normally this is used when starting a board, by selecting all subcircuits
and then dispersing them.  This scatters the subcircuits around the board
so that you can pick individual ones, rather than have all the
subcircuits at the same 0,0 coordinate and thus impossible to choose
from.
<p>
When the first argument is "buffer", rearrange subcircuits within the
buffer so they form a tightly packed rectange centered at the buffer
origin. This is useful after the initial import schematics: from sch-rnd
cross-select a bunch of subcircuits making up a functional block of the
design (e.g. a PSU section), cut to buffer, DisperseElements(buffer) then
paste at a spot of the empty board.