Added README and COPYING

The files are fairly standard. Build instructions based on the thread http://forums.openmediavault.org/viewtopic.php?f=13&t=1790
and hopefully a good starting point.

Please make sure to read the part about licensing and copyright (at the very top of the README). I have made the assumption that the plug-in follows the policy of Debian and the FSF with a GPLv3+ license and distributed copyright.