lexer size [was: Much simplified lexer]

[David Relson]

Looking back at older versions of bogofilter, I found the following:

E?SMTP\ id\ .*	;

which means that ESMTP and SMTP lines were being ignored.

The current code simply returns the token if header_line_markup is
enabled.  Since header_line_markup is the default state, the normal
action is just to return the token.  Sicne that is the same thing that
bogofilter would do without the special rule, I've removed the rule.