This enables support for devices that have a different VID/PID
than the Saleae Logic, and yet another after firmware upload.
After firmware upload is checked every 100ms whether it came back,
instead of always waiting for 2 seconds.
If the kernel attaches a driver to a device we know, detact it first.
We should use these (internal) functions in libsigrok exclusively from
now on, i.e. no more use of glib's g_debug() etc.
These functions are only for libsigrok, the frontends use whatever
logging mechanism is suitable there.
Bert Vermeulen
Uwe Hermann