* Provide some GNUisms as extensions.
* Provide dynamically growable string space.
* Make define(defn(foo)) work correctly for builtins.
(The current version is supposed to be capable of satisfying autoconf.)
All still relevant NetBSD changes have been preserved in this version, and
formatting and style fixes have been applied in various places.
Thanks to Masao Uebayashi <uebayasi@soum.co.jp> for pointing this out.
it uses pbstr() instead of doing the characters individually (in
reverse order) with putback().
Fix dodiv() so that divert(<out-of-range stream>) doesn't cause "divnum" to
return 0, but rather the stream number specified to divert(). Macros
like PUSHDIVERT/POPDIVERT rely on this. The new behaviour is compatible
with vendor m4 implementations.
