Log Message:
Update samba4 to version 4.6.4.

Pkgsrc changes:
 * Adapt PLIST, new .so installed.

Upstream changes:

Changes since 4.6.3:
---------------------
o  Volker Lendecke <vl@samba.org>
   * BUG 12780: CVE-2017-7494: Avoid remote code execution from a writable
     share.

Changes since 4.6.2:
--------------------
o  Michael Adam <obnox@samba.org>
   * BUG 12743: s3:vfs:shadow_copy2: vfs_shadow_copy2 fails to list snapshots
     from shares with GlusterFS backend.

o  Jeremy Allison <jra@samba.org>
   * BUG 12559: Fix for Solaris C compiler.
   * BUG 12628: s3: locking: Update oplock optimization for the leases era.
   * BUG 12693: Make the Solaris C compiler happy.
   * BUG 12695: s3: libgpo: Allow skipping GPO objects that don't have the
     expected LDAP attributes.
   * BUG 12747: Fix buffer overflow caused by wrong use of getgroups.

o  Hanno Boeck <hanno@hboeck.de>
   * BUG 12746: lib: debug: Avoid negative array access.
   * BUG 12748: cleanupdb: Fix a memory read error.

o  Ralph Boehme <slow@samba.org>
   * BUG 7537: streams_xattr and kernel oplocks results in
     NT_STATUS_NETWORK_BUSY.
   * BUG 11961: winbindd: idmap_autorid allocates ids for unknown SIDs from
     other backends.
   * BUG 12565: vfs_fruit: Resource fork open request with
     flags=O_CREAT|O_RDONLY.
   * BUG 12615: manpages/vfs_fruit: Document global options.
   * BUG 12624: lib/pthreadpool: Fix a memory leak.
   * BUG 12727: Lookup-domain for well-known SIDs on a DC.
   * BUG 12728: winbindd: Fix error handling in rpc_lookup_sids().
   * BUG 12729: winbindd: Trigger possible passdb_dsdb initialisation.

o  Alexander Bokovoy <ab@samba.org>
   * BUG 12611: credentials_krb5: use gss_acquire_cred for client-side GSSAPI
     use case.
   * BUG 12690: lib/crypto: Implement samba.crypto Python module for RC4.

o  Amitay Isaacs <amitay@gmail.com>
   * BUG 12697: ctdb-readonly: Avoid a tight loop waiting for revoke to
     complete.
   * BUG 12723: ctdb_event monitor command crashes if event is not specified.
   * BUG 12733: ctdb-docs: Fix documentation of "-n" option to 'ctdb tool'.

o  Volker Lendecke <vl@samba.org>
   * BUG 12558: smbd: Fix smb1 findfirst with DFS.
   * BUG 12610: smbd: Do an early exit on negprot failure.
   * BUG 12699: winbindd: Fix substitution for 'template homedir'.

o  Stefan Metzmacher <metze@samba.org>
   * BUG 12554: s4:kdc: Disable principal based autodetected referral detection.
   * BUG 12613: idmap_autorid: Allocate new domain range if the callers knows
     the sid is valid.
   * BUG 12724: LINKFLAGS_PYEMBED should not contain -L/some/path.
   * BUG 12725: PAM auth with WBFLAG_PAM_GET_PWD_POLICY returns wrong policy for
     trusted domain.
   * BUG 12731: rpcclient: Allow -U'OTHERDOMAIN\user' again.

o  Christof Schmitt <cs@samba.org>
   * BUG 12725: winbindd: Fix password policy for pam authentication.

o  Andreas Schneider <asn@samba.org>
   * BUG 12554: s3:gse: Correctly handle external trusts with MIT.
   * BUG 12611: auth/credentials: Always set the realm if we set the principal
     from the ccache.
   * BUG 12686: replace: Include sysmacros.h.
   * BUG 12687: s3:vfs_expand_msdfs: Do not open the remote address as a file.
   * BUG 12704: s3:libsmb: Only print error message if kerberos use is forced.
   * BUG 12708: winbindd: Child process crashes when kerberos-authenticating
     a user with wrong password.

o  Uri Simchoni <uri@samba.org>
   * BUG 12715: vfs_fruit: Office document opens as read-only on macOS due to
     CNID semantics.
   * BUG 12737: vfs_acl_xattr: Fix failure to get ACL on Linux if memory is
     fragmented.