[RELEASE] Released version 1.3.23

[RELEASE] Released version 1.3.23

Released version 1.3.23 with the following main changes :
    - [MINOR] server tracking: don't care about the tracked server's mode
    - [MEDIUM] appsession: add the "request-learn" option
    - [BUG] Configuration parser bug when escaping characters
    - [BUG] appsession: possible memory leak in case of out of memory condition
    - [MINOR] config: don't accept 'appsession' in defaults section
    - [CLEANUP] Keep in sync "defaults" support between documentation and code
    - [BUILD] warning ultoa_r returns char *
    - [CLEANUP] format '%d' expects type 'int', but argument 5 has type 'long int'
    - [BUG] config: fix erroneous check on cookie domain names, again
    - [DOC] trivial fix for man page
    - [BUG] config: fix wrong handling of too large argument count
    - [BUG] config: disable 'option httplog' on TCP proxies
    - [BUG] config: fix erroneous check on cookie domain names
    - [BUG] config: cookie domain was ignored in defaults sections
    - [MINOR] config: support passing multiple "domain" statements to cookies
    - [BUG] x-original-to: name was not set in default instance
    - [BUG] config: fix error message when config file is not found
    - [MINOR] config: don't report error on all subsequent files on failure
    - [BUILD] Makefile: make without arch-specific optimizations
    - [BUG] halog: fix segfault in case of empty log in PCT mode
    - [CLEANUP] second fix for the printf format warning
    - [BUG] check_post: limit analysis to the buffer length
    - [MINOR] http: typos on several unlikely() around header insertion
    - [CLEANUP] buffers: wrong size calculation for displaced data
    - [MINOR] config: option forceclose is valid in frontends too
    - [BUG] http: fix cookie parser to support spaces and commas in values
    - [MINOR] config: some options were missing for "redirect"
    - [BUILD] appsession did not build anymore under gcc-2.95 (cherry picked from commit 1fac75385abdfe03d7d3c4c5b04eb95a0db1bc74)
    - [MINOR] http: fix double slash prefix with server redirect
    - [MINOR] http redirect: add the ability to append a '/' to the URL
    - [MINOR] config: indicate that timeout appsession should not be used
    - [DOC] remove several trailing spaces
    - [CLEANUP] stream_sock: MSG_NOSIGNAL is only for send(), not recv()
    - [BUG] check: we must not check for error before reading a response
    - [CLEANUP] buffers: remove remains of wrong obsolete length check
    - [CLEANUP] http_server_error() must not purge a previous pending response
    - [MEDIUM] add the "force-persist" statement to force persistence on down servers
    - [MINOR] http: logs must report persistent connections to down servers
    - [MINOR] buffer_replace2 must never change the ->w entry
    - [MINOR] buffers: buffer_insert_line2 must not change the ->w entry
    - [MEDIUM] checks: make the HTTP check code add the CRLF itself
    - [MEDIUM] checks: add the server's status in the checks
    - [DOC] add some build info about the AIX platform
    - [CLEANUP] config: do not allocate an empty argument for rsp* keywords