* S, ( addr len -- addr' len )

ALLOT room and store the Forth string into data space as a packed string,
leaving data space aligned; and leave the length and new body address. It
is assumed that len is unsigned. An error is thrown if len is larger than
the system parameter MAX_SCOUNT. "s-comma"
NOTE: MAX_SCOUNT is returned by 
Perhaps this restriction should be removed in favor of the normal data
space overflow error.
NOTE: S, is the same as STRING, in Wil Baden's Tool Belt, except it
stores a packed string instead of a counted string.

dstrings ordinary primitive