rfidiot should not exit at module import time

[rhertzog]

There are many tools which expect that all Python modules can be imported without any side-effect. Unfortunately rfidiot is not in that category, when you import the module it will exit with an error messages like this one:

There is no such reader #0, PCSC sees only 0 reader(s)

In Kali Linux, we got this bug report showing an application feature that is broken by rfidiot:
https://bugs.kali.org/view.php?id=4056

Please refactor the code to avoid such side effects at import time.

[rhertzog]

FWIW, this is caused by

RFIDIOt/rfidiot/__init__.py

Line 194 in 4eaf194

card= RFIDIOt.rfidiot(readernum,readertype,line,speed,timeout,rfidiotglobals.Debug,noinit,nfcreader)

and

RFIDIOt/rfidiot/RFIDIOt.py

Line 100 in 4eaf194

os._exit(True)