flex version

[John W. Eaton]

On 27-Oct-2000, I wrote:

| It would be better, but it was easier to just make the check in lex.l
| using flex macros.

Thinking about it a bit more, I'm not sure that it is worth writing a
configure check for this if you are just going to check the version
number, since what is really needed is a check to make sure that flex
has the required feature(s) or doesn't have the bug(s) that prompted
me to require 2.5.4.  Unfortunately, I don't have a record of that,
only the following lame-o ChangeLog entry, which doesn't help much.

  Fri Feb 21 15:35:18 1997  John W. Eaton  <address@hidden>

          * lex.l: Require flex 2.5 or later (we really want 2.5.4 or later,
          but there seems to be no good way to check the patchlevel).

jwe