Append a text by breaking it into words and appending a sequence of tbox
objects and hbox objects
representing spaces. The name of this method is inspired by SGML, where
CDATA is used to declare character data.
If ignore_blanks is leading, first all leading blank
characters are skipped. Words encountered in the string are added as
instances of the class tbox
using the specified style. Sequences of spaces, tabs and newlines are
mapped to a single hbox
object. If the space argument is provided, this is used for
representing these spaces, otherwise a default stretchable hbox
object is created with the dimensions of a space in the current font.
See also parbox->append, tbox->initialise
and class hbox.
