This adds proto_num to request_info. It is defaulted to HTTP 1.0 (1000)
such that it has a valid value even if the underlying sapi doesn't set it
correctly. It is then used to determine if a 302 or a 303 should be sent
on a Location redirect. Any non GET/HEAD HTTP 1.1 redirect will get a 303
instead of a 302 to be compatible with the HTTP spec.
used to return "" and not bool(false). It's not worth keeping it because
STR_FREE() and zval_dtor() always have to check for it and it slows down
the general case. In addition, it seems that empty_string has been abused
quite a lot, and was used not only for setting zval's but generally in
PHP code instead of "", which wasn't the intention. Last but not least,
nuking empty_string should improve stability as I doubt every place
correctly checked if they are not mistakenly erealloc()'ing it or
calling efree() on it.
NOTE: Some code is probably broken. Each extension maintainer should
check and see that my changes are OK. Also, I haven't had time to touch
PECL yet. Will try and do it tomorrow.
