WORD -- a Read one word from buffered input and push its
addr. Always null terminated. If ASCII EOT is
encountered, a will point to it (it is cons-
idered a word).
There are also ascii const emitters:
BS CR LF SPC CRLF
NL is an indirect word (see B80) that aliases to CRLF by
default and that should generally be used when we want to emit
a newline.
