Add new pySim.ota library, implement SIM OTA crypto

This introduces a hierarchy of classes implementing

* ETS TS 102 225 (general command structure)
* 3GPP TS 31.115 (dialects for SMS-PP)

In this initial patch only the SMS "dialect" is supported,
but it is foreseen that USSD/SMSCB/HTTPS dialects can be
added at a later point.

Change-Id: I193ff4712c8503279c017b4b1324f0c3d38b9f84

setup.py

@@ -18,7 +18,8 @@ setup(
         "bidict",
         "gsm0338",
         "termcolor",
-        "colorlog"
+        "colorlog",
+        "pycryptodome"
     ],
     scripts=[
         'pySim-prog.py',