BUG/MINOR: acl: fix improper string size assignment in proxy argument

This minor bug was found using the coccinelle script "da.cocci". The
len was initialized twice instead of setting the size. It's harmless
since no operations are performed on this empty string but needs to
be fixed anyway.
DOC: add missing options to the manpage

Document -L, -v(v), -C, -dS and -dM, as they were missing from the manpage.

Signed-off-by: Apollon Oikonomopoulos <apoikos@gmail.com>
DOC: add manpage references to all system calls

Add a man section to every system call reference, giving users pointers to the
respective manpages.

Signed-off-by: Apollon Oikonomopoulos <apoikos@gmail.com>
DOC: update manpage reference to haproxy-en.txt

The manpage refers to haproxy-en.txt, which is obsolete. Update the reference
to point to configuration.txt, together with the location on Debian systems.

Also capitalize "Debian".

Signed-off-by: Apollon Oikonomopoulos <apoikos@gmail.com>
DOC: remove -s and -l options from the manpage

These options are no longer supported since 1.3, so remove them from the
manpage.

Signed-off-by: Apollon Oikonomopoulos <apoikos@gmail.com>
DOC: ssl: update build instructions to use new SSL_* variables

Since commit 9a05945bd ("BUILD: add SSL_INC/SSL_LIB variables to force the
path to openssl") we have SSL_INC and SSL_LIB to point to the libssl
installation.

This commits updates the build instructions in README accordingly.