twisted u_name and m_name

Fix Bug#523.

Additional Info:
The following line in ofork.c may also be wrong.

    /* Somone has used write_fork, we assume file was changed, register it to file change event api */
    if (ofork->of_flags & AFPFORK_MODIFIED) {
        struct dir *dir =  dirlookup(ofork->of_vol, ofork->of_did);
        bstring forkpath = bformat("%s/%s", bdata(dir->d_fullpath), of_name(ofork));
        fce_register(FCE_FILE_MODIFY, bdata(forkpath), NULL, fce_file);
        bdestroy(forkpath);
    }
Add indication to help string that --with-ldap takes an optional path
DSI_SERVQUANT_DEF is 1048576 now
Don't force S_ISGID for directories on FreeBSD, bug #525
Fix error handling when trying to set ACL on not existing rfork
Add support for ZFS ACLs on FreeBSD with libsunacl

From FR#83.
Active Directory LDAP queries for ACL support

AD stores users and groups under the same subtree which broke our naive
search strategy. Add LDAP options "ldap user filter" and "ldap group filter".

Fixes Bug #526.
Explanation of "veto message" is wrong.

and some fixes.
Option "vol dbnest"

When set to true, the CNID database for a volume is stored in the volume root
of a share in a directory .AppleDB like in Netatalk 2. Defaults to false.

From FR#84.
Small fix in the DSI tickle handling

Due to a regression introduced in 9355ebcc5744bbd445a0c8cb8b0a0ca201d5499a
the server may send an extra DSI tickle immediately after a "volume modified"
DSI attention notification. This will only happen if the connection is

o completely idle, and
o the volume was modified by another AFP client

The result is an extra DSI tickle every 30 seconds.

Fixes bug #528.
Enhance handling of connection attempts when hitting the connection limit

Bug #529.
Fix off-by-one connection limit check
Fix variadic macro syntax
Fix error in ad_openat(), bug #532

Saving from Word to a folder that is a symlink to a folder on another filesystem
results in a crash of the afpd process and the save to fail. This happens only
if the option "follow symlinks" is enabled.
Remove debug log statements
Add warning about folllow symlinks and crossing filesystems
Disable Kerberos UAM if AFP service principal name can't be evaluated

Fixes bug #531.
Fix handling of large number of volumes

o ensure only a maximum of 255 volumes is returned
o ensure the reply with the volume list fits in a certain buffer
  size, testing with 10.8.4 saw the maximum size the client would
  accept to be ~4600 bytes

Fixes bug #527
New configure option --with-tdb