this changes how ATR is handled.
the ATR is also printed when set (as important debug information).
the test is also updated to correspond to the new mechanism (
simulating the timeout before sending the ATR)
Change-Id: I69df797e2feadffa9f5f977cb71b69386cee7cd0
We now generalize the USB communiction and abandon the 'req_ctx'
structure inherited from openpcd. Instead we use the libosmocore 'msgb'
structure to handle incoming and outgoing USB tranfers. We also use
linuxlist-based msgb-queues for each endpoint.
