libusb <= 1.0.8 does not implement a reference counter in libusb_init()/libusb_exit() for the default context.
libusb <= 1.0.8 does not implement a reference counter in
libusb_init()/libusb_exit() for the default context.

We then use our own and unique libusb context.


git-svn-id: d8b078d517c8be834637447f210d7177f0fa38d6@5077 0ce88b0d-b2fd-0310-8134-9614164e65ea

LudovicRousseau/CCID,hiranotaka/ccid-scr331-nttcom,LudovicRousseau/CCID,hiranotaka/ccid-scr331-nttcom,hiranotaka/ccid-scr331-nttcom,LudovicRousseau/CCID,hiranotaka/ccid-scr331-nttcom