MINOR: compression: acl "res.comp" and fetch "res.comp_algo"

Implements the "res.comp" ACL which is a boolean returning 1 when a
response has been compressed by HAProxy or 0 otherwise.

Implements the "res.comp_algo" fetch which contains the name of the
algorithm HAProxy used to compress the response.
BUG/MEDIUM: stats: fix a regression when dealing with POST requests

In 1.5-dev17 (commit 1facd6d6), we reorganized the way HTTP stats
requests are handled. When moving the code, we dropped a "return 0"
which happens upon incomplete POST request, so we now end up with
the next return 1 which causes processing to go on with next
analyser. This causes incomplete POST requests to try to forward
the request to servers, resulting in either a 404 or a 503 depending
on the configuration.

This patch fixes this regression to restore the previous behaviour.
It's not enough though, as it happens that the stats code is handled
after all http header processing but in the same function. The net
effect is that incomplete requests cause the headers manipulation to
be performed multiple times, possibly resulting in multiple headers
in the request buffer. Since the stats requests are not meant to be
forwarded, it's not an issue yet but this is something to take care
of later.

A remaining issue that's not handled yet is that if the client does
not send the complete POST headers, then the request is finally
forwarded. This is not a regression, it has always been there and
seems to be caused by the lack of timeout processing when waiting
for the POST body. The solution to this issue would be to move the
handling of stats requests into a dedicated analyser placed after
http_process_request_body().

Bug reported by Guillaume de Lafond.
BUG/MEDIUM: Fix crt-list file parsing error: filtered name was ignored.

Also add support for multiple filtered names on same certificate (per line).
BUG/MINOR: fix unterminated ACL array in compression

Recent commit 727db8b4 was lacking a NULL ACL descriptor to terminate
the array, causing a random behaviour upon startup. No backport is needed.
BUG/MINOR: config: "source" does not work in defaults section

Source function will not work with the following line in default section:
     source 0.0.0.0 usesrc clientip
even that related settings by iptables and ip rule have been set correctly.
But it can work well in backend setcion.

The reason is that the operation in line 1815 in cfgparse.c as below:
     curproxy->conn_src.opts = defproxy.conn_src.opts & ~CO_SRC_TPROXY_MASK;

clears three low bits of conn_src.opts which stores the configuration of
'usesrc'. Without correct bits set, the source address function can not
work well. They should be copied to the backend proxy without being modified.

Since conn_src.tproxy_addr had not copied from defproxy to backend proxy
while initializing backend proxy, source function will not work well
with explicit source address set in default section either.

Signed-off-by: Godbach <nylzhaowei@gmail.com>

Note: the bug was introduced in 1.5-dev16 with commit ef9a3605
BUILD: last fix broke non-linux platforms

src.tproxy_addr only exists on linux.
BUG/MEDIUM: ssl: EDH ciphers are not usable if no DH parameters present in pem file.

Uses default defined DH parameters when none present in pem file.
MINOR: init: indicate the SSL runtime version on -vv.

It happens that openssl's API can differ between versions, causing some
serious trouble if the version used at runtime is not the same as used
for building.

Now we report the two versions separately along with a warning if the
version differs (except the patch version).
BUG/MEDIUM: shctx: makes the code independent on SSL runtime version.

struct SSL(ssl_st) defintion changed between openssl versions and must not be dereferenced.
BUG/MEDIUM: compression: the deflate algorithm must use global settings as well

Global compression settings (windowsize and memlevel) were only considered
for the gzip algorithm but not the deflate algorithm. Since a single allocator
is used for both algos, if gzip was first initialized the memory with parameters
smaller than default, then initializing deflate after with default settings
would result in overusing the small allocated areas.

To fix this, we make use of deflateInit2() for deflate_init() as well.

Thanks to Godbach for reporting this bug, introduced by in 1.5-dev13 by commit
8b52bb38. No backport is needed.