Lack of support for Python3

[kszys]

It seems that ibanlib does not support Python3 at the moment. There are a few issues I managed to identify:

• importing ConfigParser module, which has been renamed to configparser in Python3. This only needs to be changed in a couple of places.
• string.maketrans does not exist in Python3 - and str.translate only takes 1 argument, so (allchars, ' ') needs to be replaced by (str.maketrans('','',' '))
• there is no longer long type in Python3 - needs to be replaced by int

If needed, I can create a pull request.