multiline response handling

[geo-rg]

This is a first approach to handle multiline responses from Chameleon properly. I first tried to send the EOT character but minicom printed it to screen which has been annoying.

This solution does the following: It sends a NULL-Byte right after a transmission has been finished (minicom ignores this). The chamtool now tries to obtain data until it reads a NULL-Byte. The latter one might look dangerous, but it should work as long as the firmware works. However, I'm not too familiar with efficient python, maybe someone knows how to handle this better?

Another idea would be to send this NULL-Byte before the final "\r\n", maybe this is better?

[geo-rg]

I can already see a problem with the identify command. This first calls CommandLinePendingTaskFinished, which sends the NULL-Byte at its end, but then it adds some information (ATQA etc.), so chamtool would miss these additional information.