Add support for preserving ACL entries of files.

Add support for preserving ACL entries of files.

* net/tramp.el (tramp-file-name-for-operation): Add `file-acl' and
`set-file-acl' handlers.

* net/tramp-adb.el (tramp-adb-handle-copy-file): Handle
PRESERVE-EXTENDED-ATTRIBUTES.

* net/tramp-compat.el (tramp-compat-copy-file): Handle
PRESERVE-EXTENDED-ATTRIBUTES.

* net/tramp-gvfs.el (tramp-gvfs-file-name-handler-alist): Add
`file-acl' and `set-file-acl' handlers.
(tramp-gvfs-handle-copy-file): Handle
PRESERVE-EXTENDED-ATTRIBUTES.
(tramp-gvfs-handle-file-acl, tramp-gvfs-handle-set-file-acl): New
defuns.

* net/tramp-sh.el (tramp-sh-file-name-handler-alist): Add
`file-acl' and `set-file-acl' handlers.
(tramp-remote-acl-p, tramp-sh-handle-file-acl)
(tramp-sh-handle-set-file-acl): New defuns.
(tramp-sh-handle-copy-file, tramp-do-copy-or-rename-file): Handle
PRESERVE-EXTENDED-ATTRIBUTES.

* net/tramp-smb.el (tramp-smb-file-name-handler-alist): Add
`file-acl' and `set-file-acl' handlers.
(tramp-smb-handle-copy-file): Handle PRESERVE-EXTENDED-ATTRIBUTES.