usbip: tools: Start using VUDC backend in usbip tools

Modify userspace tools to allow exporting and connecting to vudc.

This commit is a result of cooperation between Samsung R&D Institute
Poland and Open Operating Systems Student Society at University
of Warsaw (O2S3@UW) consisting of:

   Igor Kotrasinski <ikotrasinsk@gmail.com>
   Karol Kosik <karo9@interia.eu>
   Ewelina Kosmider <3w3lfin@gmail.com>
   Dawid Lazarczyk <lazarczyk.dawid@gmail.com>
   Piotr Szulc <ps347277@students.mimuw.edu.pl>

Tutor and project owner:
   Krzysztof Opasiak <k.opasiak@samsung.com>

Signed-off-by: Igor Kotrasinski <i.kotrasinsk@samsung.com>
Signed-off-by: Ewelina Kosmider <3w3lfin@gmail.com>
[Various bug fixes and improvements]
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>