renamed VERSION precompiler identifier to VERSION_TBAPI to resolve conflict with global package VERSION identifier created by autoheader
set autogenerated files (Makefiles, ...) to be ignored by git
fixed/worked around hang on Close(): under some conditions, the ftdi_usb_close() and ftdi_deinit() calls would hang;
implemented timeouts of 1s each so that the software does not freeze on exit.
tests show that the device correctly responds on the next restart of the software, so no negative impact has been seen so far in case the timeout is hit.