DOC: stats: document the comp_rsp stats column

This was forgotten in recent patch 5e16cbc3.
BUILD: buffer: fix another isprint() warning on solaris

This one came with commit recent be0efd8. Solaris wants ints, not chars.
MINOR: cli: add support for the "show sess all" command

Sometimes when debugging haproxy, it is important to take a full
snapshot of all sessions and their respective states. Till now it
was complicated to do because we had to use scripts and sessions
would vanish between two runs.

Now with this command we have the same output as "show sess $id"
but for all sessions in the table. This is a debugging command only,
it should only be used by developers as it is never guaranteed to
perfectly work !
BUG/MAJOR: cli: show sess <id> may randomly corrupt the back-ref list

show sess <id> puts a backref into the session it's dumping. If the output
is interrupted, the backref cannot always be removed because it's only done
in the I/O handler. This can randomly corrupt the backref list when the
session closes, because it passes the pointer to the next session which
itself might be watched.

The case is hard to reproduce (hundreds of attempts) but monitoring systems
might encounter it frequently.

Thus we have to add a release handler which does the cleanup even when the
I/O handler is not called.

This issue should also be present in 1.4 so the patch should be backported.
MINOR: cli: improve output format for show sess $ptr

This change removes pointers for known types (stream_interface, ...),
adds buffer pointers and sizes, and moves buffer information to their
own line. The output is cleaner with shorter lines and slightly more
lines.
[RELEASE] Released version 1.5-dev14

Released version 1.5-dev14 with the following main changes :
    - DOC: fix minor typos
    - BUG/MEDIUM: compression: does not forward trailers
    - MINOR: buffer_dump with ASCII
    - BUG/MEDIUM: checks: mark the check as stopped after a connect error
    - BUG/MEDIUM: checks: ensure we completely disable polling upon success
    - BUG/MINOR: checks: don't mark the FD as closed before transport close
    - MEDIUM: checks: avoid accumulating TIME_WAITs during checks
    - MINOR: cli: report the msg state in full text in "show sess $PTR"
    - CLEANUP: checks: rename some server check flags
    - MAJOR: checks: rework completely bogus state machine
    - BUG/MINOR: checks: slightly clean the state machine up
    - MEDIUM: checks: avoid waking the application up for pure TCP checks
    - MEDIUM: checks: close the socket as soon as we have a response
    - BUG/MAJOR: checks: close FD on all timeouts
    - MINOR: checks: fix recv polling after connect()
    - MEDIUM: connection: provide a common conn_full_close() function
    - BUG/MEDIUM: checks: prevent TIME_WAITs from appearing also on timeouts
    - BUG/MAJOR: peers: the listener's maxaccept was not set and caused loops
    - MINOR: listeners: make the accept loop more robust when maxaccept==0
    - BUG/MEDIUM: acl: correctly resolve all args, not just the first one
    - BUG/MEDIUM: acl: make prue_acl_expr() correctly free ACL expressions upon exit
    - BUG/MINOR: stats: fix inversion of the report of a check in progress
    - MEDIUM: tcp: add explicit support for delayed ACK in connect()
    - BUG/MEDIUM: connection: always disable polling upon error
    - MINOR: connection: abort earlier when errors are detected
    - BUG/MEDIUM: checks: report handshake failures
    - BUG/MEDIUM: connection: local_send_proxy must wait for connection to establish
    - MINOR: tcp: add support for the "v6only" bind option
    - MINOR: stats: also report the computed compression savings in html stats
    - MINOR: stats: report the total number of compressed responses per front/back
    - MINOR: tcp: add support for the "v4v6" bind option
    - DOC: stats: document the comp_rsp stats column
    - BUILD: buffer: fix another isprint() warning on solaris
    - MINOR: cli: add support for the "show sess all" command
    - BUG/MAJOR: cli: show sess <id> may randomly corrupt the back-ref list
    - MINOR: cli: improve output format for show sess $ptr