Add sample C code which shows how to use new functionality
of libusbg - gadget export. This program allows to export
chosen gadget from configfs to a file.
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
[Port from libusbg and update description]
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
