Changed addresses to reflect new domain openambit.org
Log most likely reason why device cannot be opened.  Re #26

Device communication requires read/write access permissions no matter
how you look at it.  Looking at the innards of `hid_open()` shows that
that function calls `open()` with the same flags as well.
Add call to `close()` to match `open()` introduced in 4799eab
Merge remote-tracking branch 'allfather/master' into Qt5_Client