pySim pytlv dependency

Hi Philipp, just now I'm trying to use pySim to read a SIM card, but I notice: ImportError: No module named pytlv.TLV I can find no pytlv in the debian packaging; and I notice this dependency was added only recently. When going back to 859e0fd1ce08699930064c12fb9f7908ef972b50 I can use pySim fine without that. a) I think the readme should hint at dependencies that pySim requires, which should include pytlv and where to find it. b) In python, it is easy to import pytlv only in case it is actually used, which would simplify dependencies for users that don't need to "get file/record length from FCP (USIM)" -- would that make sense? What are your thoughts? ~N