torture: add smb2 FSCTL_[GET/SET]_COMPRESSION test

torture: add smb2 FSCTL_[GET/SET]_COMPRESSION test

This test simply creates a file and checks the compression state before
and after FSCTL_SET_COMPRESSION(COMPRESSION_FORMAT_DEFAULT).

The test expects the compression state to be COMPRESSION_FORMAT_LZNT1
after set, conforming to Windows Server behaviour.

If the server responds to the first FSCTL_GET_COMPRESSION request with
NT_STATUS_NOT_SUPPORTED or NT_STATUS_INVALID_DEVICE_REQUEST, then the
test is skipped. This allows it to run during selftest.

Signed-off-by: David Disseldorp <ddiss@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Fri Aug  9 22:03:39 CEST 2013 on sn-devel-104